Tag Archives: PCP

Air & C02 Rifles and Pistols

Setting Up & Testing the GX CS4 PCP 400 Bar/5,800 PSI Air Compressor

In the last post I discussed purchasing a new GX CS4 compressor and showed you some photos of it out of the box. In this post, I want to give you some recommendations on setting the unit up and testing it. There are definitely details around the CS4 that you need to know and it is critical you don’t just take it out of the box and try to start using it.

Read the Instruction Pamphlet

There should be a small pamphlet in with the CS4. Take a minute and read the instructions for use. Afterwards read the following.

Distilled Water or Antifreeze for Cooling?

So the pump gets its really long duty cycle in no small part due to the liquid cooling system. Liquid is a far, far more efficient conductor of heat than air is. You see, water is much more dense than air and depending on the article you read it is 9 to 13 times more efficient at carrying away heat – maybe even more.

In the automotive world, to lower the freezing point and raise the boiling point, various chemicals have been discovered and are often referred to generically as “antifreeze”. You look deeper though and there are tons of variations for different manufacturers and different specifications.

GX said to use either distilled water or a PH-neutral antifreeze. Well, I wasn’t sure how hot the pump would get so I was worried about using distilled water. The benefits of distilled water is that it is cheap and it is PH neutral being neither acidic nor alkaline so it’s not going to cause excessive corrosion. On the other hand, it can freeze or boil like any other water plus there aren’t any corrosion inhibitors or pump lubricating agents.

I was very keen to use an antifreeze for longer life plus I was worried about boiling. I didn’t plan to keep the pump outside so freezing wasn’t a worry. The problem began when I tried to find “PH-neutral” antifreeze. I could not find any antifreeze with a true PH of 7. I turns out that you will be hard pressed to find it – I found cutting fluids (coolants for doing metal cutting) with a PH of 7, brake line antifreeze that had a PH of 7 — it was almost pure methanol, but not a thermal transfer fluid that I could buy in small quantities (like 1-2 gallons).

The more digging I did the more I realized that I could use an automotive antifreeze but needed to find one with a relatively low PH (7-9) and also that contained corrosion inhibitors and was aluminum and plastics & hose friendly. To make a long story short, this led me to Valvoline’s Zerex G48 coolant and I opted for a 70/30 mix of coolant to distilled water. My local Napa autoparts store was able to order in a gallon jug with same day in store delivery. It’s a fortune to mail order but only $14-17/gallon at a store.

Do not add it to the unit yet! You will need to test and flush the cooling system first

I thought I had it all figured out. I had premixed a 500ml 70/30 solution. That means 350ml was G48 and 150 was distilled water. I’ll explain why this didn’t work out the way I had hoped further down.

Powering It Up

Before you get to far, plug the AC-to-DC adapter in the wall. You should hear the cooling fan turn on — it definitely needs it so if you don’t hear the fan make sure there is AC power through the power cord to the adapter. There isn’t an on-off switch – the unit should turn on as soon as you plug it in.

Put a multimeter on the power supply terminals and you should see around 13 volts. My CS3 power supply is 13.16 volts and the CS4’s power supply which is the same model just newer measures 13.06 volts.

Make sure the CS4’s switches are off before you connect the compressor to the power supply.

Flushing the Liquid Cooling System

The nut with viewing glass that covers the water tank should just be on hand tight. If you must, use a wrench to remove it but just put it on hand tight when you re-install it going forward. The system is not pressurized – you can take the cap off while it is operating.

For some reason my CS4 shipped with a little bit of water in it – maybe from testing at the factory and there was also some kind of brownish sediment on the bottom of the “water tank”.

This is what I saw when I removed the cover to the water tank. It should be shiny silver so you can see there is some kind of brownish sediment.

The liquid had no smell and felt like water – I have to guess it was water so I just dumped it out. I then refilled the tank with clean distilled water and swirled it around. I did this four times until the water stayed nice and clean.

For testing and flushing the system, just use distilled water. It’s cheap and doesn’t make a huge mess if there is a problem or something spills. Been there, done that – use water – trust me. By the way, purified water may not be distilled – the purified water might just be filtered. Distilled water uses a process that not only purifies the water but has the minerals removed as well. You don’t want minerals to leave a scaly buildup so use distilled.

The fluid return is near the top and you fill the water or antifreeze to the bottom of it.

I then turned the unit on and watched the water – nothing happened. There is a water pump – the intake is in the center bottom of the tank and the return is on the side about 3/4ths of the way up – there was no water moving. Oh man … I started to get really worried that maybe the water had frozen and snapped the pump but everything was dry when I took it out of the box … but …. stuff happens.

The water intake is at the bottom. Now this is where I got nervous – notice there is no water movement. I knew from the diagram that there was a pump. I could hear the unit’s fan running but there was no way to hear or feel if the pump was. I started to wonder if the pump didn’t have power, had cracked or something else.

I started to take the case’s screws off to look inside. At one point, I leaned the unit part way over to get to a bottom screw and heard the familiar “glug glug glug” sound of water running into a void that previously had air in it. That was a very, very welcome sound because it dawned on me that the little water pump had lost its prime.

I looked at the water tank and the water level had definitely gone down. I turned on the pump’s main switch and the pump started moving the water! Lesson learned there – prime the pump.

This is what it looks like when the pump is working. The sediment blew out of the lines too so then I realized I needed to flush the system again. I did this a number of times until the water was clear.

The next thing was that brown sediment was entering the tank as the lines blew out in the unit. I then dumped out the water and flushed the lines three more times until everything looked clear. Each time I would wiggle the compressor around leaning it slightly from side to side and front to back until the pump would prime. You fill the water tank to the bottom of the return line. This gives room for the coolant to expand and it also gives you a visual cue if the pump is working.

Now this told me something – there would be more water in the unit than just what was visible in the tank. In the instruction pamphlet they say you need to add 500ml of liquid to the unit. The unit came with some amount of water in it and each time when I drained the unit, I was only adding back in about 130 ml of water each time – I was using a 1000ml graduated cylinder for all of this. So, 500-130=370ml of trapped water in the system. Hmmm…. this was throwing my planned antifreeze ratios all off. 500ml of fluid at a 70/30 ratio would mean 350ml of antifreeze and 150ml of distilled water. I was going to be off and you need enough water in an antifreeze for the chemicals to move around properly.

In general, 100% pure antifreeze concentrate is a bad idea – there is a ratio you need to follow either based on the temperature range you need or what the vehicle manufacturer recommends. With G48, most vehicle makers recommend a 50/50 mix and there is actually a premixed formula with a typical PH of 8.1 (the range is 8-9). I was going for 70/30 to have as low of a PH as possible (pure G48 has a PH between 7.1-7.3) and to maximize corrosion protection.

After dumping the final batch of distilled water out of the unit, I could only put in just over 130ml. This cylinder had 500ml of the 70/30 mix before pouring.

Well, the trapped water was throwing a wrench in my plans because I had already mixed the 70/30 not realizing I would have a bunch of extra water in the jacked and lines. Rather than drive myself nuts, I decided to go ahead and test the unit by draining out whatever water I could my tilting/moving the machine around while it was upside down and then refill with 70/30. After testing I will drain the tank get the antifreeze ratio closer to 70%.

I was not able to collect the final PH at this time. My test strips are absolutely useless with the dark blue of the G48 fluid. A friend has a calibrated digital tester that we will use some time in the future.

As I was writing this blog post, I was talking to my friend John, who is a master mechanic and has forgotten more than I will ever know, and told him about this. He didn’t even have to think about it – he said “pull a vacuum through the inlet or return and drain the system”. Duh. He was spot on – I sure hadn’t thought about doing that.

I used a MityVac MV-6830 brake line bleeder to suck all of the liquid out through the inlet. I put 70/30 in the tank and used a right angle adapter to pull all of the fluid that way. I then refilled the tank with 70/30 and pulled just enough vacuum to the point I saw fluid entering the hose and stopped – I did that last part to pull fluid into the pump.

The Mityvac MV6830 connects to an airline and uses the venturi-effect to create a vacuum. There are several lines that come with the kit – a straight siphon line that is shown above and a right angle rubber fitting for brake line fittings. Guess what? The .26-.27 outer diameter siphon line fits the inlet perfectly and I could suck all of the fluid out of the lines. I then used the right angle fitting to draw G48 through the outlet line.
The 0.26-0.27 siphon line fits the inlet perfectly.
The right angle fitting can be pushed against the return outlet to suck fluid through. It’s a bit of a challenge and takes two hands. One to hold the adapter and a finger from the other hand to apply pressure so the fitting seals enough against the return. Note, the fluid level in the tank goes down fast.

I then turned on the master switch so the fan and water pump would start. Nice clean 70/30 G48 was coming out. I slowly added more mix to the tank until I got to the bottom of the return line. I had to top it off just a tad maybe 2-3x as fluid filled little pockets. I let the unit run for another five minutes and when the fluid level stayed the same, I put the cap back on – done. It helps to have smart friends.

Here’s my lessons learned that I want to share when it comes to the cooling system:

1. Flush the cooling system out using distilled water and then use a vacuum bleeder or siphon tool to more fully drain the system. I put put about 250-350ml of fluid to fill the system in the end. The important thing is to fill the tank to the bottom of the return.

2. If you don’t see the fluid moving, you most likely need to prime the pump either by moving the CS4 around to work fluid down into the pump or draw it into it using a vacuum bleeder.

3. Test the cooling system with water – not antifreeze or you will make a mess plus water is cheaper.

4. While you can use distilled water, I would recommend Zerex G48 at either 70/30 or 50/50. I went with 70/30 that I had to mix from the concentrate.

Testing the CS4

Now that the critical coolant discussion has been addressed and you have filled the unit accordingly, let’s switch gears and start actually testing the unit. After every test, drain the unit using the bleed valve. I will bring this up again later but do not attempt to start the compressor with pressure already in the line.

There will be some very high pressures involved. If a fitting does not want to come off, STOP. Many times a quick release collar will not move or a threaded fitting turn because the line is pressurized. Always make sure the line is depressurized before you work on it, remove a fitting, etc.

Each bold heading below is a test I would recommend that you perform and if it fails, stop and contact the Amazon seller – Ankul. I am not a representative – just a user. With that said, here are the tests:

  • Make sure the fluid pump is running

Before you start pressurizing the system, again, turn on the master red switch but not the pump. You should see the coolant circulating, If you do not, try moving the unit around to get the pump to prime

  • Turn the compressor on with nothing attached

With the airline off and just the male foster fitting exposed with nothing on it, turn on the pump by pushing the top silver button. You should hear the pump start and feel air blowing out from the end of of the foster fitting rhythmically – there is a piston so the air will come out as the piston pushes upwards – it is not a continuous flow. You should not hear any awful grinding noises or banging sounds. Slight squeaks as things start to lubricate and wear in are possible – you are listening for “OMG – what the hell is that?” sounds.

Let it run for a minute or two and if no scary sounds start then shut off the compressor.

  • Test with the supplied pressure hose only

To test high pressure air systems, always pressurize incrementally starting with the smallest thing first and work your way up to larger and larger volumes. In this case, start with just the air hose attached.

This is our first real test of the compressor under pressure plus we get to check the hose assembly. With that said, connect the air line and insert the test plug in the end. Make sure the plug is fully seated. Also, make sure the drain valve / pressure relief valve is closed – this is the black knob on the front of the unit. Clockwise closes the valve – it screws closed basically.

Set the limit switch / stop switch on the top to 300 bar. Put the secondary switch at 310/320 bar. I put my second switch just before 400bar but in hindsight, I would tell you to put it around 310/320.

Turn on the compressor by pushing the silver button. You should see the pressure build very quickly – the manual says it should reach the target 300 bar pressure in 38 seconds. I think mine was a bit faster than that.

The supplied pressure hose will fill quickly for testing and will only hold a small volume of air so if something fails it will be less of a problem

Now, don’t do a thing. Watch the pressure gauge. It should just sit there – if it is going down there is a leak. The most likely culprit is the drain valve isn’t fully closed. Wait until it leaks all the way down or open the bleed valve to speed things up. You don’t need to go crazy tightening the valve knob as you are liable to hurt something but it should be firmly closed. Make sure it is snug and try again. 90+% of the time that fixes the issue.

If it still leaks drain the system, remove the test plug and look in the female foster fitting – is the rubber o-ring still down in there? Same goes for the other end of the hose that plugs into the machine. It could be missing. So, if it is, insert an o-ring and try again. If the o-rings are there, sometimes just removing and reseating a quick connect fitting/plug can solve the issue. Make sure the bleed valve is closed and try again. If it will not build pressure, contact Ankul on Amazon.

So the first limit switch at the 9 o’clock position was set to 300. The black needle is the actual pressure. Notice that the unit stops just short of the indicated pressure. The second limit switch which is the failsafe was set at about 390. In hindsight I would tell you to set that second switch just a tad higher than the first one. If I wanted the first switch to be at 300 then I would set the second one close to it at 310/320. You can’t put them right on top of each other.

Soapy water in a spray bottle can help you find where the leak is at. Do not run your hands right against the fittings or you risk air getting injected into your body and that is very bad.

By the way, I let mine sit for about 3-5 minutes before I decide. Usually a leak is really obvious in the first minute – the first few seconds even. Either it will not build pressure at all or it leaks down fast.

Bleed off any residual pressure. Opening the bleed valve also allows any trapped moisture to blow out of the drain line also. I doubt you will see it with this short of a test but you will sooner or later so don’t worry. It’s supposed to do that.

  • Test with the filter installed

Assuming the pressure line passes testing, it’s time to up the volume game and pressurize the air line and whatever external filter you want to run. I am using a big 300mm long filter with a 50mm outside diameter sold by FastToBuy on Amazon. Yes, the CS4 has an internal filter – but I really want the air to be dry.

First, make sure the system is depressurized by opening the bleed valve. Then plug your filter into the air hose and this time put the test plug on the end of the filter. All of your fittings should fit together very nicely. If you find something doesn’t want to go together, stop. Buy a replacement fitting, I like Air Venturi brand but any reputable brand will do. I’ve had Chinese no-name filters, hoses and other items with out of spec fittings that will not go together. Last month, I had a brand name fitting whip off a Hatsan Jet II and hit me in the glasses so hard that the polycarbonate lens was gouged and my glasses were flattened against my face on one side – I had tried to push the fittings together and they didn’t mate properly. Moral of the story – fitting should go together easily without forcing.

Once the assembly is together, the bleed valve is closed, set the pressure limit switches to 300 and 310 bar then turn on the compressor. It may take it a minute or two for enough pressure to build up to show on the pump’s pressure gauge. It may take a few more minutes depending on how big the filter is before it reaches 300 bar. As before – stop and watch the pressure gauge, it should hold steady and not leak down. If it does, then check the bleed valve, o-rings, etc.

Testing the big inline filter. It is very nicely made and comes with a spare filter cartridge.

The absolute most common source of leaks is at the fittings – worn or missing o-rings or one fitting not really sealing well against another and you then need to decide which fitting to replace. Soapy water in a spray bottle can help you find where the leak is at. Do not run your hands right against the fittings or you risk air getting injected into your body and that is very bad. Notice the repeat on that safety comment.

If everything passes, open the bleed valve to dump the air in the filter and line.

  • Time to Fill The Tank

Part of my push for the new CS4 was to also fill my new 6.8L 4500 PSI Airmarksman tank. I really wanted to go with a new Omni or Patriot (US made Omnis) but the 6.8L model is hard to find so I went with Airmarksman because I really wanted two gauges – one with line pressure and the other with tank pressure. Standard single gauge units just show you line pressure.

It’s nice, the Air Marksman’s air hose attaches via a quick connect. I can go right from a female foster fitting on an airline right into the tank – no more little male-to-male quick connect fittings that are easy to lose.

I also bought a really nice 3′ long Manloney air hose extension to go from the new filter to the tank. In general, I am not a fan of hanging a filter right on a fitting because you create a long lever arm that is too easy to snag and break. Instead, I prefer a hose to the filter and then a hose from the filter into the tank.

You know what this means right? I tested the Manloney hose extension by inserting the test plug, and doing everything we’ve talked about previously.

Tested the Manloney hose extension and everything was good.

I then bled the air off and let the unit’s cooling system run until the exhaust temperature was the same as surrounding surfaces because it was time to get real. Filling the tank from empty to 300 bar would take at least 2.5 hours and I wanted to record times, pressures, temperatures and and decibel readings along the way.

Filling the tank. Note – do not put the power supply in front of the exhaust fan. I noticed it was getting quite warm and moved it to the side a while after this photo was taken.
This is the pressure gauge on the tank. It read higher than the compressor so I followed it for safety’s sake. In other words, I did not want to exceed the rated 310 bar on the bottle – I actually only went to 300 bar – but if I had followed the gauge on the pump I would have gone higher. Which gauge was right / more accurate? No idea but I will always play it safe to not avoid a stated safety limit. By the way, the thank has another gauge on the back and they both agreed with one another.
This table shows you what I noted during testing. I just did the fill one time.

I couldn’t just sit next to the compressor and tank for the 3 hours and 22 minutes the test was running. I set the shut off on the pump to 300 bar but what I found was the needle you are moving around to shut off the pump is not precise. For example, I wanted 300 bar but what I got was 257 bar of 3,725 PSI. I then ran the unit another 10 or 15 minutes to take it up to 300 bar even and then moved the limit switch / shut off needle slowly backward until it stopped. Now the first switch is set where I want it. The second need is just behind it by about 10-20 bar.

The temperature management is remarkable. I was using a very good Fluke infrared thermometer to measure the exhaust fan area’s temperature and once it got up to about 100 degrees it pretty much stayed there once the unit warmed up. The noted coolant temperatures were collected by me removing the lid of the water tank and using the Fluke infrared thermometer to get a reading.

Speaking of temperature – this ran far cooler than I thought it would. I actually thought the fluid would get hotter and risk boiling. I still like using antifreeze for the corrosion protection and lubrication of the pump but boiling is not a concern and I don’t foresee it ever being some place where it could freeze but I guess lowering the freezing point is a good idea just in case.

In terms of sound, the unit turned on with just the fan and coolant pump running is 71DB according my BAFX 3608 decibel meter. The sound level with the compressor running was in the 82-84DB range about 8-10 inches from the side of the unit – not bad at all. I thought it might get louder as the pressure increased but it didn’t.

Last comment – the unit ran for well over 3 hours and thirty minutes – probably more like 4-4.5 with all of the testing. There were no funny sounds, no unexplained leakages, etc. That amount of running gave me a real good impression of the unit. After all of that running, I did turn the grease pot one rotation.

Special Note: DO NOT Start or Re-start The Compressor Under Load!

GX stated in multiple places to not try and start the pump with the system pressurized. I imagine it puts too much strain on the electric motor and other parts to get spinning. When I did the top off fill mentioned above, I closed the tank’s valve and opened the bleed valve on the compressor to depressurize the line. Unsurprisingly, maybe a teaspoon or two of water came out as well. I then closed the bleed valve, started the compressor and after it came back up to speed only then did I re-open the tank valve and put the system back under load.

By the way, I am not surprised by this at all. With shop air systems, part of the pressure limit switch is to also open a bleed off valve to depressurize the pump. It’s fairly common for these switches and valves to wear out. If the air doesn’t bleed off then a breaker may trip given the increased load. So, giving the CS4 a chance to start without a load and come up to speed first makes sense to me.

Summary

I was really impressed by the smaller CS3 model that I have used since November 2020. I bought this new CS4 model because I had such a good experience in fact and now that I have run the CS4 over four hours, I’m pretty happy. The CS4 will fill the niche in the GX line-up for a medium-duty machine for 6.8 Liter and smaller bottles. The CS3 will continue to be sold for people filling 1.5L or smaller cylinders.

Wrapping up – I really like the unit so far and will definitely post updates as time goes on.

Here are the GX compressors from the CS4 down to the CS1

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Air & C02 Rifles and Pistols

The Next Generation GX CS4 PCP Air Compressor Is Amazing!

Life is a funny thing – I grew up with firearms. Yeah, my dad had these two old pump action Daisy airguns that were fun to shoot tin cans with but starting at a pretty early age I liked things that went “bang”! Sometime in the early 2000s, I got back into airguns to deal with pests. I started hearing about a class of airguns called “pre-charged pneumatics” (PCPs) that used 3,000 PSI high pressure air cylinders somewhere on the rifle to propel the pellet. They were reported to be accurate, reliable and capable of rapid repeating fire through through the use of a manually operated bolt and a magazine.

I thought that sounded so neat – especially the rapid follow up shots. What stopped me from buying one was that they had to be refilled from a SCUBA tank that was filled at a diving shop. Well, I eventually found out there were specialized hand pumps and you didn’t need to spend a fortune on a tank and hassles with going to the dive shop. I bought a Hill Mk.4 hand pump along with a .22 Hatsan Gladius Long that I used for a few years.

Along the way, I found out that high pressure air compressors were falling in price. Those things used to be well past a $1,000, large, noisy, heavy and there was just no way I could swing one. In the fall of 2020 while surfing around on Amazon, a very affordable high pressure air compressor was doing really well. It was affordable, getting great reviews, portable and I didn’t have to mess with all kinds of oils and ice water cooling baths. It was the CS3 air compressor from GX. I bought one for $529.99 on November 23, 2022 – Amazon is cool in that I can search order history and pull up dates that I would have forgotten otherwise.

I wrote a post about buying it and also one about setting it up and testing it. I almost always used the CS3 to top off a really nice little Omni 18 cubic foot tank that I would then use to fill my growing number of PCP airguns. It really worked well – the tank was really convenient to pull out and top off an airgun and I would only occasionally need to bring out the CS3. Sure, I could have filled the airguns directly from the CS3 but I wanted to keep things simple.

Fast forward to January 2023 – I bought a .30 Umarex Gauntlet with a big cylinder and was planning to get one or two other high air consumption PCP rifles in 2023 so I started thinking about how to feed them. It was a total coincidence that GX unveiled their next generation CS4 compressor on Amazon. There were just a few four or five reviews at the time and I decided to gamble on the new pump and bought it on January 29, 2023. I took the leap because I had such a positive experience with the CS3 and I knew I could return it to Amazon if it turned out to be a problem child. [Yes, I bought this so you are getting my honest observations – click here for the Amazon CS4 product page.]

On January 31, 2023 the Amazon driver brought be a big heavy cardboard box with the GX CS4 and I started getting my stuff together to do some testing plus a time slot to fill a big 6.8L carbon fiber tank from empty to 300bar which would take 2-3 hours I figured.

Now, I’m going to tell you something – it is slick. It is really, really slick. I’m telling you this so you take the time to read more in this post plus one about setting it up and testing it.

What is the GX CS4?

The CS4 is an additional pump offering from GX for people wanting to fill larger cylinders than the CS3. It also reflects design advancements to the CS3 unit – here are the features that really caught my eye:

CS3CS4
Working Pressure
(Mfg supplied)		30MPa/300 bar (4,351 PSI)40MPa/400 bar (5,801 PSI) – 33% more pressure
Air volume
(Mfg supplied)		7 liters/minute (0.247 cubic feet/min)11 liters/min (0.388 cubic feet/min) – 57% more air volume output
Suggested Maximum Air Cylinder Size2.5 Liters6.8 Liters
CoolingAir with fansCoolant with radiator and fan
Power
(Mfg supplied)		12V 250 Watts12V 350 Watts – 40% more watts
Duty Cycle (Mfg supplied)30 minutes working and 20 minutes cooling5 hours continuously working. Manual says to let it run for 1-2 minutes after pumping is complete – 10x longer duty cycle.
Sound Level (Mfg supplied)75db70db
Pump lubricationNot needed (until it slows down – mine hasn’t so far)Has a grease pot to add grease every 4-6 hours of run time
Limit switchSimple rotary dial limit switchProtected twin pin design where you can set both the limit and failsafe limit
Hose19.6″ permanently attached hose19.6 hose that is removable via a quick connect foster fitting
Weight (my digital scale)19.4 pounds29 pounds with antifreeze – 55% heavier
Dimensions (me with a tape measure)5-3/8″ wide (about 5-7/8″ wide including the wire spool on the side) x
9-1/2″ deep (10-1/4″ if you include the release valve) x
10-1/2 high at the top of the case (about 11-1/2 overall if you include the handle)		6″wide case (6-1/2″ wide with the wire spool) x
11-78 deep (12-3/4 if you include the release valve) x
12-1/2″ at the top of the case (about 13-1/2 at either the top of the grease pot or the folded handle) – about 62% larger overall

For me, the really long duty cycle is what I was looking for. The 57% increase in air output is a welcome enhancement to have over the CS3. Since I would fill my guns from my tank, I was never in a rush. Now that I have 6.8L tank, the fills will probably be less often but a lot more volume will be needed so it’s good to get that increase.

The increase in air pressure is overkill right now – there aren’t affordable 400 bar working pressure tanks as of yet – they are out there for specialty applications but are in the $1,500-2500 range. I’m sure the price will come down over time but most carbon fiber air tanks that PCP shooters are using are in the 300-310 bar working pressure range. If you see 400 bar, read the ad again because they may be talking about the test pressure and not the working pressure – you fill to the working pressure only – never to the test limit.

To be clear, the GX CS4 is not replacing the CS3. They have added the CS4 to fill larger tanks faster. They identify the 6.8 liter tanks as being the target max size for the CS4 and for me the duty cycle is the more important number. You can fill anything you want as long as you don’t bake the pump.

With the CS3 for example, the 20 minute duty cycle is what limits a convenient tank size. If I needed to fill my Omni 100 cu in (1.64 liter) tank from empty – I would let it run for 20 minutes and then I would stop the pump but let the fan run until it cooled down to room temp. I’d then close the cylinder valve, bleed the air out of the line, start the air pump again and as it came up to speed I would open the cylinder’s valve again. It took a while but it worked just fine. I tried to always be mindful of the duty cycle and give the unit a chance too cool down before I either shut it off or resume – I’m sure that’s one reason I’ve had zero problems with the CS3 since I bought it.

A five hour duty cycle with the CS4 is pretty amazing. I’ll tell you more about it when we get into the setup and testing.

Out of the Box Pictures

Let’s take a look here:

The CS4 was well packed. Amazon’s delivery group sometimes smashes delicate packaging so I was glad to see the unit was well protected in a plastic bag with styrofoam holding and protecting everything inside of the box.
They are using the same 12 volt 46.2 amp power supply. This allows you to either power the pump with a car/truck battery or use this power supply to charge at home. You can see the removable air hose under it still sitting in the styrofoam.
This is really nice. With the GX CS3, the air hose is bolted to the unit and gets in the way at times. With the GX CS4, there is a standard Foster quick connect. Notice the thought put into the hardline portion on the left side of those – this is the end that plugs into the pump and the metal line bends at an angle thus avoiding collapsing or weakening a flexible airline. It’s a well thought out change.
Starting from the top back – the silver cylinder is the grease pot that you use every 4-6 hours to introduce grease into the cylinder. The brass fitting is the safety burst disc. A burst disc plays an important safety role – it will blow out before an extreme pressure situation could cause a catastrophic failure of the pump. The clear circle has the pressure gauge and the two limit switches you can set. On the left is the power wire spool. The silver nozzle sticking out is the male foster fitting that the quick connect air hose goes to. On front side (colored black) – top right are the on/off switches for the pump itself. The red master switch turns the unit on and both the fan and coolant pump begin working. The black knob is the pressure release / bleed valve. Behind the circular slots sits the CS4’s radiator that has a fan cooling it – the antifreeze/distilled water flows through it to cool off.
The pressure gauge and limit switches surprised me. I went to rotate the switches by turning the silver knob and immediately felt a weird springy resistance. On the CS3 I always checked the pressure because if you bumped the knob the pressure limit changed. Well, now move the top silver “finger” around and push down to turn either limit switch. It’s less prone to being bumped and you have two limits – not just one. It’s not absolutely goof proof but I think it is a good next step from a safety perspective.
With high pressure systems, play it safe. My tank gauge vs. the pump’s gauge don’t match so I go with the higher of the two pressures. It’s called “conservativism” – go with the most conservative or safe number given the situation – don’t base your fill on the low-reading gauge, go with the one that says there is more air pressure just to be safe. In my shop’s air system I probably have a dozen pressure gauges and they all read slightly differently – I guess it is just the nature of the beast unless you want to spend a mint on calibrated accurate gauges.
On the back of the unit are vertical slots and when you look in you can see the cooling fins of the first stage cylinder liner.
The larger CS4 is on the left and the CS3 is on the right. The CS4 is intended for filling up to 6.8L bottles and the CS3 is targeted for smaller bottles and/or airguns. Note: GX makes two versions of the CS3 now – one with the external 12 volt power supply like I have as well as one that just plugs directly into the wall and does not have a 12 volt supply.
CS3 on the left vs the CS4 on the right.
One last comparison photo – the CS3 is on the left, the CS4 is on the right and the dogs’ water bowl is in the back 🙂 See how the air hose just dangles on the CS3? Being able to remove it completely from the CS4 really cleans things up plus opens the door for future hoses should you need them.

Here are the GX compressors from the CS4 down to the CS1

Summary

The CS4 compressor is a great new product offering from GX. Click here to see it on Amazon.

In the next blog post I will walk you through setting the unit up and then testing. I’ve already done all of this so I’m telling you right now the CS4 is a solid unit. In the next post I’ll explain why I am so impressed along with what I did to set up and test it.

1/28/24 Update: Had to fix Amazon links so they work in the list above the summary. I’m still using my CS4. No problems.

6/12/23 Update: Fixed the wording about being conservative. Thanks KG!

Note, I have to buy all of my parts – nothing here was paid for by sponsors, etc. I do make a small amount if you click on an ad and buy something but that is it. You’re getting my real opinion on stuff.

If you find this post useful, please share the link on Facebook, with your friends, etc. Your support is much appreciated and if you have any feedback, please email me at in**@ro*********.com. Please note that for links to other websites, I may be paid via an affiliate program such as Avantlink, Impact, Amazon and eBay.

Air & C02 Rifles and Pistols

Boy Did I Get Lucky – Foster Coupler Blew Off Just Over 3,200 PSI And Hit Me In The Glasses

Time for a safety briefing and, yes, I am the cause of the briefing. This is not a blame game post – what happened to me will likely happen to me again and may happen to you as well. The important thing is to learn from it because I got real, real lucky.

I was topping off my new Hatsan Jet II with high pressure air from my Omega tank for maybe the dozenth time or more and thought I was being careful. I am respectful of high pressure air because I am a NAUI certified SCUBA diver and sometimes weld right with Gas, MIG and TIG torches. I have heard plenty of stories over the past 40 years (yeah, I am that old) about tanks, fittings and what not. Guess I got sloppy this time.

I connected the DonnyFL female foster fitting to the male foster fitting on the Jet II and gave a gentle tug to make sure it was seated. You always want to do this by the way. I really didn’t think a lot about it because I have refilled from a tank so many times. Bad routines can lead to bad outcomes and it did here.

I was holding the Jet II off at an angle where I could see the manometer (what they call the pressure gauge in the high pressure / pre-charged-pneumatic (PCP) airgun world. I’d guess the angle was about 30-45 degrees and may 18 inches away – these are all best guesses in hind sight.

I cracked open the valve and was doing a slow controlled fill. Somewhere just over 225 bar (3,263) PSI, the hose’s female fitting explosively slipped off the male fitting on the airgun and rocketed off. It happened so fast that I realized my face was numb, I had taken a direct hit in the polycarbonate right lens of my glasses and had heard something like a gun shot. I turned off the air and went to the bathroom to look in the mirror expecting to see blood. I was geniunely surprised there wasn’t any so then I started looking.

My right lens had a gouge where the fitting hit it and saved my eye. I had a small light bruise on my eyebrow but it really wasn’t bad. Luckily, I had spare glasses and grabbed them to be able to see.

This is the lens after my optometrist bent things back correctly and cleaned then lens. The gouges are there to stay. I told her what happened and she told me I was very lucky to be wearing polycarbonate lenses because they can handle an amazing amount force.

What happened?

My next thought was “what the hell just happened?” The O-ring from inside the DonnyFL female quick connect foster fitting was still on the Jet II’s male foster fitting. Nothing had broken – no tears, missing metal or rounded edges.

I was the victim of stacked tolerances. This means that any given specification has a +/- allowance that the machinist can go over or under by and still be ok. The stacked tolerance problem is when you have those tolerances of parts combine to then be outside of specification. Please notice that I am not blaming any of the vendors.

The DonnyFL female quick connect foster adapter, which works fine on my Air Venturi fittings and FX Impact Compact Mk II had slightly different dimensions than the Hatsan male fitting. I had noticed since I first bought the Jet II that I needed to firmly seat the DonnyFL female fitting as it didn’t go on easy. With 20/20 hindsight, I should have realied that was a bad sign and switched to the supplied Hatsan female quick connect fitting. I didn’t make the change befoe because I thought the DonnyFL and was good to go since it worked on everything else. Turns out that was a wrong assumption.

I really don’t know why more harm wasn’t done. Maybe the fitting flew straight out, the end of the hose was reached and it whipped back with less energy. Maybe because my glasses flattened around my eye socket it partially absorbed and then distributed the force. I can tell you I feel real lucky that worse didn’t happen.

What did I do as a result?

All of my air fittings are made by Air Venturi – I buy different configurations of them and keep them in stock so that when I have a fitment problem I can change to an Air Venturi fitting.

In this case, I wasn’t about to take the Hatsan apart so I took the Hastan supplied female fitting and put an Air Venturi male quick connect on the end to get a solid connection both to the airgun and to the DonnyFL quick connect. The fittings go together very smoothly and I’ve not had problem after almost a dozen top offs.

The DonnyFL female foster fitting is above. The Hatsan female foster fitting with the Air Venturi male plug installed is at the bottom.
This combination seems to work really well. The DonnyFL works great with Air Venturi fittings and the Hatsan female foster works great with the Jet II’s make foster fitting.

Summary of Lessons Learned

The problem of stacked tolerances will always be around and thus one brand of fitting may not work well with another. So here are the lessons learned.

  1. Be mindful that when you have to push a foster fitting on harder than normal then that likely indicates the fitment is wrong and you must look at your options.
  2. Use the airgun supplied adapter (if they give you one) and then put a brand of fittings on it that allow you to safely mate the parts together if there is a fitment issue.
  3. I will use the pressure gauge on the tank and not the airgun going forward even though I thought I was at a safe angle.
  4. Do not get anywhere near the fitting during refills – especially with your head or face.

I hope this helps you out. It was a wakeup call for me.

If you find this post useful, please share the link on Facebook, with your friends, etc. Your support is much appreciated and if you have any feedback, please email me at in**@ro*********.com. Please note that for links to other websites, I may be paid via an affiliate program such as Avantlink, Impact, Amazon and eBay.

Air & C02 Rifles and Pistols

Update on the Hatsan Jet II – It’s Pretty Wicked!

I wrote a series of posts about purchasing a .22 Hatsan Jet II right after I bought it in early January 2022. After shooting it for a month I have some feedback to share.

I’d guesstimate I have just over a 100 rounds through it. I’ve changed quite a few 7 round mags – that much I know for sure. The first thing I want to tell you is that the performance and reliability are surprising. It reinforces to me that Hatsan can turn out some great airguns.

The Shroud Is True

I was a little worried about how true the shroud would be relative to the center of the barrel’s bore. In my Gladius, it was not. With the Jet II, it is. The way you can tell is that pellets are landing all over the place because they hit the adapter or somewhere in the moderator and spin out of control. In other words, accuracy is horrible until you remove the moderator and/or the adapter. The DonnyFL 1/2-20 male to male adapter screwed right and then the Hugget Sniper to it and accuracy was great.

Accuracy

Speaking of accuracy – I was very happy. Once I dialed in the scope I had no problem shooting 1/2″ 7 round groups using 18.13 JSB Exact Jumbo Diabolo pellets at 12 yards from a bench. To be clear – just me resting my arm on the bench. I didn’t have a true rifle stand.

That is 7 rounds of .22 18.13gr JSB Exact Jumbo Heavy Diabolo pellets at s12 yards. Ignore the blatant flier – that was my fault, not the gun’s or the pellets. I was firing supported from a bench but the Jet II was not in a bench rest. I’ll do some accuracy testing one of these days.

Now, another form of accuracy is to tell you about squirrells. I have cleanly dispatched 8 over the last three weeks. Distances vary from 12-16 yards.

The Jet II really likes these pellets. I really like JSB in general for all of my pellet guns.

The Charging Handle

In my first review I voiced a concern about the polymer charging/cocking lever. So far, it has worked just fine – no signs of any loosening or bending.

The cocking handle is doing just fine.

Air Use

I purposefully bought the Jet II due to the larger air reservoir than the Jet I. I could shoot two mags with no noticeable change in trajectory in my 12 yard test range shooting 18.13 JSB Exact pellets.

My usual approach is to shoot a mag and then top of the Jet II from my air tank at the same time I reload the pellets in the magazine. I have a spare magazine ready to go so if I was in a rush for some reason I know I have a little bit of buffer just in case I need it – I’m using the gun for pests and not target shooting.

I had it filled pretty close to the 250 bar max. What you see is the amount of air left after 14 shots (two magazines). I have not tried shooting more than two mags after refilling.

Snipe Moderator

I’m using the Hugget Snipe moderator and it almost makes the Jet II backyard friendly. It’s far quieter with it of course – I just wish it was quieter yet and will experiment some more with different cans.

The Hugget Snipe does a very good job. I wish it was even more quiet but that’s not really a negative reflection on the Snipe.
With the Snipe, the overall length is approximately 30″. From an overall length perspective, it’s a great combination.

Summary

At this point I am still very happy with the Jet II for it’s intended pest control purposes. It’s definitely effective and amazing for the price when you stop and think about it.

Here’s the listing at Pyramyd Air and I always recommend you use their 10 for $10 test service:

Hatsan Jet II 0.22

Hatsan Jet II 0.22

Hatsan Jet II Convertible PCP Pistol

Convertible pistol or rifle Includes removable synthetic stock PCP Two 40cc air cylinders fill to 3,625 PSI/250 BAR Shots at optimal velocity*: 48 (.177), 42 (.22), 30 (.25) Magazine capacity: 8 rounds (.177), 7 rounds (.22), 6 rounds (.25) Integrated manometer Max. velocity (lead-free): 810 FPS (.177), 700 FPS (.22), 611 FPS (.25) Max. velocity (lead): 788 FPS (.177), 700 FPS (.22), 608 FPS (.25) Max. energy: 9.7 FPE (.177), 15.6 FPE (.22), 16.5 FPE (.25) Length-adjustable buttstock Elevation-adjustable cheek rest Ridged rubber buttpad Flip-up fiber optic front sight Flip-up adjustable fiber optic rear sight 11mm Dovetail optics rail Picatinny accessory rail Barrel length: 7.9" Overall length (pistol): 15" Overall length (rifle): 22.8"-24.6" Overall weight (pistol): 2.4 lbs. Overall weight (rifle): 3.4 lbs.

* – within 85% of peak velocity.

Note, I have to buy all of my parts – nothing here was paid for by sponsors, etc. I do make a small amount if you click on an ad and buy something but that is it. You’re getting my real opinion on stuff.

If you find this post useful, please share the link on Facebook, with your friends, etc. Your support is much appreciated and if you have any feedback, please email me at in**@ro*********.com. Please note that for links to other websites, I may be paid via an affiliate program such as Avantlink, Impact, Amazon and eBay.

Air & C02 Rifles and Pistols

JSB Airgun Pellets Are My Favorites – Two Cool Factory Tour Videos

In addition to firearms, I like pellet guns and use them quite a bit for pest control. Along the way, I’ve had a chance to try quite a few different varieties of pellets and do have a favorite maker – JSB, For my needs, they have worked great in both break barrel springs as well as precharged pneumatic (PCP) which is pretty much all I use now.

Like with firearms, you need to find the brand, style and weight of pellet that works best for your needs be it plinking, punching paper or hunting. For example, the main PCP airgun I use is a FX Impact Compact Mk.II in .25 caliber. I’ve found the JSB Exact King .25 Diabolo 25.39 grain pellets work exceptionally well for that rifle both in terms of accurace and the ability to deal with squirrels, rabbits and the occasional raccoon.

I’ve looked at these 25.39 grain JSB pellets and often wondered how they are made

Who Makes Them?

I knew they are made in the Czech Republic – I got that much right but I thought JSB was the company and that is only partly right. The company was founded in 1991 by Josef Schultz (the “JS” part of the name), who was a competive shooter and coach, with the express intent to make airgun ammunition. The “B” is from the town he lived in – Bohumin.

The current company’s name is “JSB Match Diabolo Bohumin” and was a merger of Josef’s pellet making activities as well as others – if I understand some of what I read, he design some of the machines and they are all under that “JSB Match Diabolo A.S.” corporate name, which was established in 2007 in the town of Bohumin.

On a sad note, Josef passed away due to complications following a surgery in 2020 at the age of 76. He definitely left a legacy behind.

Videos

Lately I’ve been watching a lot of airgun videos on Youtube and encountered two different videos that have factory tours of JSB that are fascinating.

This first one is three years old and has the most detail including explanations by a tour guide in English:

This second one is shorter, set to music, has some really great details and is from early 2022:

Summary

Thought I would share these neat videos with you and hope you enjoy them. Kudos to the folks who took the time to put them together for us.

Note, I have to buy all of my parts – nothing here was paid for by sponsors, etc. I do make a small amount if you click on an ad and buy something but that is it. You’re getting my real opinion on stuff.

If you find this post useful, please share the link on Facebook, with your friends, etc. Your support is much appreciated and if you have any feedback, please email me at in**@ro*********.com. Please note that for links to other websites, I may be paid via an affiliate program such as Avantlink, Impact, Amazon and eBay.

Air & C02 Rifles and Pistols, Shooting in General, Uncategorized

The ATN X-Sight 4K 5-20x Scope Is Surprisingly Effective But Expect A Learning Curve

I never was that interested in ATN scopes until maybe a two years ago. I was at the range fiddling with something and a fellow pulled in and set up a varmint AR with a big blocky optic on a Bog Deathgrip tripod. I could not help myself – I had to go over and ask what the optic was.

Thankfully, he was a good old boy and liked shooting and talking. He was having a coyote problem and wanted to get the rig sighted in. He told me it was an ATN night vision optic and the tripod was to help him keep it all steady. I looked it all over and headed back to my area. The ATN looked better in person than it did in the ads that I had seen in catalogs that made it look “gimicky”. Between my assumption about the quality and the price, I was never interested but after seeing it in person it was filed under “who knows – maybe someday” category in my head for future projects.

Fast Forward to 2021

I was researching high end airguns and some of the of guys were running various ATN scopes. I wanted to up my game on the computational ballistics front – yeah the calculation of trajectories – and I wanted a computer to do it for me. I really wanted to get surgical and modern with my new .25 caliber FX Impact Compact pre-charged pneumatic (PCP) air rifle. This desire brought me to ATN and their latest generation of digital X-Sight 4K optics because they have an internal computer that can crank the numbers.

An Auxiliary Ballistic Laser (ABL) good from 5 to to 1000 yards could be added that interfaced with the scope to provide range to target data to the computer. The computer can take the muzzle velocity of your round, the ballistic coefficient of your bullet (in my case pellet), distance of the optic from the center of the bore, angle and the distance to the target and automatically adjust the recticle. Whoa…. that’s pretty amazing.

Just a quick note on the ABL – based on my experience with laser rangefinders, usually maximum range comments by vendor are a bit of hype because it depends on how reflective the target is. In my case, virtually all of my shooting will be within 50 yards with a possible stretch to 100 but I doubt I will ever shoot beyond that.

Another feature that attracted me was the night vision capability. I’ve not had the capability to eliminate pests at night or at very low light levels.

The X-Sight scopes have a host of other features like taking photos and movies, recording just before and after sensing recoil, etc. Those are nice but not really features I cared about.

I shopped around and ordered an ATN X-SIght 4k 5-20x optic, Auxiliary Ballistic Laser (ABL) 1000 rangefinder, and a quick release mount. It came to just over a $1,000 plus I bought a SD memory card. The optic and rangefinder were from Brownells and I sourced the quick detach mount direct from ATN. A lot of vendors carry ATN products so you can shop around.

In case you are wondering why I would go to such expense for accuracy in a PCP airgun that will mostly be used within 100 yards, I can sum it up with the saying “aim small – miss small.” It’s one of my favorite lines from American Sniper but it is true. If you focus your aim on a very small part of the target then you will either hit it or miss by a small amount. This requires discipline and knowledge on your part combined with a capable weapons system to deliver the bullet or pellet.

The Scope, ABL and Mount Arrived

When the boxes came and I started reading the manuals, I had the same feeling when I read something that says “some assembly required”. I really hadn’t put much thought into how different a digital optic is from a traditional scope. Wow. This thing has a series of setup menus and then you need to learn your away around the scope. So right out of the box there was a lot of fumbling, swearing and my changing things.

So here’s my first recommendation – be sure to watch ATN’s videos about setting up the optic and using it. The manuals help but I found the combination of videos for the overview and the documentation to refer to as a very handy combination. Click here to go to the ATN page with all of their videos and/or click here for the manuals – it actually has links to PDFs videos and guidance on the page itself.

The X-Sight is mounted just like any other scope. Square the weapon then the optic to the weapon to ensure the recticle is level. I use a Wheeler scope mounting kit’s leves to do this. Note that the Impact Compact is being held in a Tipton Standing Ultra GunVise. Man, those are nice.

Here’s an example of needing to read the instructions. The threaded portion is part of a tube that is separate from the body of the ABL. You back off the two screws you see, remove the tube and screw it into the front of the X-Sight scope. You then clamp the ABL onto the tube and position it horizontal to the scope and bore.

Here is everything mounted.
Here’s another angle.

Now let me give you hope – once you start using the scope, it gets easier and faster each time. I turn on the scope so it has time to boot up as I am setting up – not at the last minute when I need to take a shot. Most of the time I am shooting at 14 yards so I dont need to range the target and the scope remembers the last range used. Instead,I zoom as needed, acquire the target and take the shot. That’s it – not a billion menus. So, stick with it – you will probably find it frustrating too at first and then it will get better with time.

Setup and Zeroing In Tips

When you are entering the info for the ballistic coefficient (BC) and the muzzle velocity, try and be as exact as possible, I obtained the BC from the manufacturer of my .25 pellets and the muzzle velocity was the average of 10 rounds fired through a chronograph.

I carefully measured out the range from the muzzle to the target. When I entered the range into the optic, I was precise and not guessing. I was being very careful due to the desire for accuracy.

Set your rifle up in a firm stand and fire a group then adjust the recticle. Their marketing comment of one shot zeroes is something they even mention is “in theory”. Repeat this until you have your zero consistently. This will all go faster and be easier if you have a solid stand – notice I mentioned this twice now 🙂 I used a Bog Deathgrip Carbon Fiber model to help me get the job done.

My Opinion

I’ve been using the X-Sight since late-April 2021 and like it. If I have a new distance to shoot, I range it, take the shot and then reset to my most common distance. I have made a few 35-50 yard shots that would have required some calculation, or at least experience, and hit less than quarter sized targets (squirrel head and heart shots) accurately.

Here’s another angle that gives you a good view of the mounted ABL. It connects to the scope via Bluetooth and you need to follow a zeroing process outlined in the manual. It’s straight forward but don’t skip it.

One thing I had to get used to was looking at a small monitor vs. glass. I’ve been shooting nice glass scopes for a number of years now – notably Vortex scopes – and looking at a monitor with a resolution lower than reality is different. I must admit that I prefer the clarity of good glass but it dawned on me that it was not fair to compare them at this point. I bought the ATN for the ballistics calculation capabilities and the potential for low-light/night-use — I did not buy it to be just another scope, That set my mind more at ease about the image difference – it is what it is with the current level of technology in these scopes.

This is an actual screen capture. The optic allows you to select from a number of recticle choices. Note the range information from the ABL down in the ower right corner. What you see in the scope actually has much more information but the screen capture does not include it.
This is an exciting shot of concrete but it lets you see the recticle better.

The combination of scope and ABL is a bit bulky and the ABL’s head is asymmetrical for the laser transmitter and receiver units. I set the Impact Compact on our tall kitchen table and it fell off onto the hardwood floor about three feet. It definitely made my stomach drop to hear all that money hit the floor. I’m actually happy to report that the rifle and optics system survived without any problems at all.

I was wondering how long the battery would live but that has not proved to be a problem. I fully charged it when I first got it and then again a few weeks ago. Now I don’t leave it turned on all the time. I’d say it runs maybe 5-10 minutes every 2-3 days and it’s not been a problem. I think I will just always charge it when it gets half way down or so plus I could always charge it from a powerbank/portable battery if needed. ATN even sells an extended battery if you need it.

The ABL is still on its first battery so I can’t tell you much there – I only use it as needed for longer shots so its had minimal use. I do have a spare battery just in case.

I wish the menus were a bit easier to navigate with very clear “back” or “cancel” options immediately available on every screen. For example, if you get into the manual ranging section or the part of zeroing the recticle by accident. For the most part they are pretty straight forward but I am not wowed by them from a user design perspective.

I opted for the ATN quick connect scope mount and it is okay but does not have locks on the throw levers. In hindsight, I could have used any 30mm rings I wanted including my preferred American Defense mounts. You have plenty of flexibility because one of the menu options lets you specify how high the scope is mounted.

Here’s a view of the ATN quick dtach mount’s levers. They don’t lock closed but have held no problem so far.

Last comment – I had the scope freeze on me twice. I found that turning the ABL off first, if I turned it on, seemed to cause the problem. Now, when I do use the ABL, I turn the scope off first and then the ABL. I’ve not had it freeze since powering down in this order. By the way, if your scope does freeze, hold down the power button for 10-15 seconds and it will shut off – kind of like notebooks where one push does a controlled power down of the laptop but holding it down does a forced immediate shut down.

ATN definitely tries to label everything outside of the scope to try and help folks learn the controls.

In Summary

I’ve been using the X-Sight 4K 5-20 and ABL 1000 laser for about three months and several times per week – sometimes several times per day depending on what is going on. I really feel like the combination has improved my actual accurage in terms of precisely hitting the target so I am happy with the purchase.

I’d recommend the setup for anyone looking for this type of optics system with similar intentions as I outlined at the start. It’s different from traditional glass lense optics but it brings a different set of capabilities to the table also. Let me put it this way,I would buy it again for my intended use.

I hope this helps you.

Note, I have to buy all of my parts – nothing here was paid for by sponsors, etc. I do make a small amount if you click on an ad and buy something but that is it. You’re getting my real opinion on stuff.

If you find this post useful, please share the link on Facebook, with your friends, etc. Your support is much appreciated and if you have any feedback, please email me at in**@ro*********.com. Please note that for links to other websites, I may be paid via an affiliate program such as Avantlink, Impact, Amazon and eBay.

Air & C02 Rifles and Pistols

FX Impact Compact .25 PCP Powerhouse – Initial Findings

In the last post, I covered my journey leading up to the purchase and arrival of the FX Impact Mk.2 Compact. The rifle performed beautifully right out of the box. The trigger was definitely very nice and the action was smooth.

For the price though,I did find some features, or lack thereof, annoying and ranked them in order from biggest pet peeve to the least:

  1. There is no “cocked” indicator and it will let you double-cock the rifle thus loading/stacking multiple pellets on top of one another. I have learned over time to carefully pay attention to the feel of the cocking handle about a 1/4-1/3rd as the absence of the spring compressing tells me it is already loaded. I also try to make sure I put the rifle immediately on safe as another flag. While mistakenly double-cocking the rifle has decreased, it still happens. When it does, I open the bolt, remove the magazine and use a cleaning rod to push them out. Come on FX, my $800 Gladius disengaged the cocking lever once cocked to avoid that user error. This my biggest beef.
  2. The owner’s manual is a bit vague. It is concerning that it says changing the power wheel when charged will damage it and void the warranty. WTF. Maybe you should fix your design instead. Putting the blame on the operator is a total cop out. Dear FX, I reached out to your customer service group asking what the power level numbers and letters correspond to with no answer.
  3. The distance from the Foster high pressure quick connect fitting to the trigger guard so long that the purchaser must go out and buy an extended length female fitting? If you find your common length female fitting below human reach once it clicks into place, remove the screws from the trigger guard, remove it, remove your coupler from the rifle and then promptly order a longer one. Tony sent one with my rifle that I wasn’t sure I would need – turns out I sure did. I later ordered an even longer knurled one that DonnyFL sells. Not the end of the world by any means but it is annoying.
  4. Your decocking feature would be nice except it leaves the pellet in the chamber and unless you pull the magazine too and remember that one is in there and shoot it before re-installing the magazine, you will double stack pellets. I’d tell anyone reading this to shoot a pellet into the ground or any other suitable stopping surface vs. using the decocker.

That’s it in terms of things I dont like and I had time to reflect on this list. All in all, it’s a pretty wicked PCP air rifle.

The DonnyFL “FX” Moderator

DonnyFL makes quality sound moderators exclusively for airguns in Oviedo, Florida. While the FX moderator that Tony included did reduce the sound levels, it wasn’t enough. I had a “Ronin” series moderator that could absorb more gas and reduce sound levels even further so I installed it on the special adapter that was already on the rifle. It definitely reduced the sound even further but was still too loud. I added in the 6″ extension and it was quieter but I want even more. I plan to purchase their biggest moderator the “Sumo” and will post about that later. So it’s not really a knock on the FX series moderator but I would tell you to at least get a Ronin of the right caliber and the correct adapter to install it.

This is the DonnyFL Ronin moderator on the left of the seam just above the end cap that is keeping the assembly from rolling. On the right is the optional extension that lengthens the moderator. It was a cheap experiment to see if ot lowered the sound level when firing and it did. I am betting the Sumo will lower it further because the extension is just a hollow tube that serves as one large expansion chamber whereas the Sumo is designed to absorb the compressed air blast the whole length.

Element Optics Helix 6-24×50 Scope

Element Optics is a sister company to FX and their goal is to make quality scopes for airgunners and even firearms. I will say that the glass is remarkably clear but I will also tell you that one day I got my air rifle out and missed the squirrel I needed to dispatch and then I missed another and another. I set up a target and the impact point had shifted almost 1.5-2″ to the right but it was consistent. My best guess was that I had accidentally turned the non-locking windage adjustment knob quite a bit. How? I have no idea.

It turns out there is a zero stop you can easily adjust to return to zero – I wish I realized this up front. It was my fault for not reading the manual up front. What I should have done was to confirm my zero, set the zero stop and then if I had any question, I could immediately return to zero. Live and learn.

Air Source

In December 2020, I invested in a GX CS3 high pressure air compressor off Amazon and it is still going strong seven months later. I run an inline filter to my 18 cu ft Omega tank and use the tank to fill the Impact Compact – I still put a filter between the tank and the airgun just to be safe – quick connects make the plumbing and moving things around real easy – I use all Air Ventury quick connects to avoid compatibility problems – I’ve had to swap out a few generic fittings along the way. Click here for various posts about the compressor and tank.

The GX CS3 compressor is geat. Here it is in refillying my Omega 18 cu ft tank. The small blue cylinder in the air lines is a high pressure air filter. I have a bigger one that I need to replace the generic male fitting with one from Air Venturi and once I do, it will be filtering the air for the tank and then the small blue fiter will filter the air from the tank to whatever airgun I am filling.

Some Photos For You

This is the Impact Compact with the DonnyFL Ronin moderator sitting directly in front of it.
Here’s another angle.
Here’s the power adjuster that I still don’t fully understand. “3” seems like a nice middle of the road setting that works on squirrels without a lot of over-penetration at 14 yards. You can also see the trigger – it’s definitely sweet and contributes to the accuracy.

In Summary

Most of my shooting is within 50 feet and the rifle is an absolute tack driver, It will takke a squirrel or rabbit out with no problem. I’m using the JSB 25.39gr pellets and with the excellent trigger, where ever I put the crosshairs the pellet follows. I’m going to stick with this base rifle for a while but I did replace the scope with an ATN X-Sight 4K that I will write about next.

Note, I have to buy all of my parts – nothing here was paid for by sponsors, etc. I do make a small amount if you click on an ad and buy something but that is it. You’re getting my real opinion on stuff.

If you find this post useful, please share the link on Facebook, with your friends, etc. Your support is much appreciated and if you have any feedback, please email me at in**@ro*********.com. Please note that for links to other websites, I may be paid via an affiliate program such as Avantlink, Impact, Amazon and eBay.

Air & C02 Rifles and Pistols

FX Impact Compact .25 PCP Powerhouse – Doing The Research

Over the years, I have slowly upped my game when it comes to airguns. My first bb gun was an old Daisy that I shot with my dad and from there I progressed to a Crosman 766 that was my trusty companion — until I got old enough and my dad let me buy my first .410 shotgun and I moved to the world of powder burners (firearms) until about 10 years ago.

For pest control reasons, I moved up from the entry-level airguns and bought a .22 caliber Diana 34P. It did the job but being a break-barrel springer, you had one shot and then had to divert your attention from the critters and reload.

From there I bought a .22 caliber Hatsan Gladius Long and Hill Mk.4 hand pump. I’d started blogging at this point so I wrote a number of posts. The rifle was relatively quiet, had a decent trigger, was accurate enough and packed a punch.

I then added a Hatsan AT-P2 that was smaller and interesting but didn’t hit squirrels hard enough. It’s still sitting in my closet in it’s case. The one thing they don’t tell you about airguns until after you get into them is that the resale value sucks – you have to practically give them away so … the AT-P2 is in the closet.

Getting back to the Gladius, it was and is a solid airgun however, I wished it was quieter so I bought an adapter and DonnyFL Ronin moderator to reduce the sound level. Turns out the barrel wasn’t true in the shroud so the pellets would hit the adapter and accuracy just disappeared so I removed the Ronin and saved it for a future airgun. It was also longer than I wanted and not regulated either meaning whatever pressure was in the tank, that affected the velocity and shot placement at the target … in short, I started to get more and more disappointed because while the Gladius is a good PCP airgun, it’s not a great airgun – at least not in terms of meeting my needs as I learned and changed what I wanted from an air rifle.

I was really leaning towards a bullpup design so I could get a longer barrel in a compact design with a relatively short overall length. I also wanted it to be regulated, have an excellent trigger, accuracy, power and to be quiet. It’s a tall ord to get all of these so I was looking at vendors like Airgun Technology, Daystate, FX, Kalibr, LCS and Taipan. I was really torn between the Vulcan, Cricket and Mutant models so I was reading everything I could – these air rifles were/are expensive and I honestly could not afford to buy one that didn’t deliver.

I usually prefer to read first hand accounts on the web and watch videos on Youtube but due to the level of investment and I am not some guru in the airgun space, I decided to call the Some airgun vendors allow people to take calls who are just order takers – they have nowhere near enough experience with the products they are trying to sell to make a credible recommendation. I’m not going to call any groups out by name but let me just recommend that you call more than one and you do your research before you buy anything – especially a higher-end air gun.

After the disappointing calls, I decided to call TalonTunes and Tony, the owner, picked up the call. Tony is an interesting guy – he has a ton of knowledge and is direct — no BS. I found it refreshing after my other experiences.

TalonTunes & The FX Compact Impact

As we talked and he understood more what I was looking for he steered me towards the FX Impact Mk.II Compact – a short barrelled design I was not familiar with and he explained he could sell me a “tuned” model for $2,499 wherein he would modify the transfer port and pellet probe plus he would dial it in for accuracy with the proper regulator pressure and sight in the scope – provided I bought the scope from him. It also came with a DonnyFL FX moderator to reduce the sound when it fired.

I wrote down the details and told him I would consider it. The answer that really sticks me months later was that I asked him if I should go with .22 or .25 for squirrels, rabbits and a rare racoon. He told me that he had plenty of customers who went with .22 who later told him they wished they had gone for the larger .25 pellet but he did not have a single customer who opted for .25 who later said they wished they had bought a .22. I’d been going back and forth in my head about which to move with and that pretty much sealed it – I would move with a .25.

Again, for this kind of money, I wasn’t going to leap on anything until I researched both the FX Impact Compact and the reputation of TalonTunes. Let’s start with the base air rifle.

FX Airguns is a Swedish company known for making progressive airguns and they seem polarize people into either being fans or not liking them at all. In general though, they are known for quality airguns and you can readily get parts for them.

The Impact was revised in 2020 with an enlarged “power plenum” located before the transfer port. The compressed air is held in it until the trigger is pulled at which time it rushes forward and propels the pellet forward. The speed is a function of the volume of air and the pressure in the plenum. Combine this with an excellent barrel and you have a powerful accurate air rifle.

It also sports a fully adjustable trigger and it uses an AR-15 grip. By using an AR grip, this opens up a world of grip options for you.

It is a bolt action repeater feeding from a 28 round removable magazine. The one thing to look at with these rifles is the magazine – the design that the Impact uses is proven and not a headache to load. Also, not all magazines are removable for quick reloads.

The Impact Compact is fully regulated too. If you aren’t familiar with regulated airguns, this is a critical accuracy selling point. The air tank “bottle”) on a PCP air rifle holds are at whatever the maximum rated working pressure is and then the pressure slowly goes down as shots are fired and air is used. The Impact Compact has a 250 bar (3,625 PSI) fill pressure. Now the regulator is governing the air pressure that makes it to the plenum so that it is a constant – in the case of my rifle it was set to 120 bar (1,740 PSI). As long as the bottle is about 120 bar, the pressure will be about 120 bar at the plenum making the shot velocity much more consistent – for a variety of reasons there will be a bit of give and take on the pressure and the resulting velocity.

In general, a regulated design is far better than an ungoverned PCP airgun that will have a sweet spot somewhere for X number of rounds and then drop rapidly. For my Gladius,it was rated at 200 bar but I would only fill it to 190 and it was pretty consistent for the first 10 rounds and then I would pump it back up to 190. It was a bit of a chore but it served me well for almost four years so don’t get me wrong.

So, for the Impact Compact, it was getting solid reviews with guys amazed at the power and accuract of the small rifle. I was pretty much sold. The only shortcoming I could foresee was the lack of a moderator but the TalonTunes package included one.

In terms of TalonTunes, Tony gets very good reviews. People posting on airgun sites mentioned that there might be a wait but what showed up was as-described and quality. I didn’t turn up any significantly concerniing reviews so I decided to move ahead.

I Placed The Order

I called Tony and ordered the tuned .25 FX Impact Compact, an Element Optics Helix 6-24×50 scope and the requisite mounting rings. Yeah, I did have to wait for Tony to tune and ship it – I think it was about 4-6 weeks but what showed up was pretty wicked and worth the wait.

The rifle arrived in two boxes. One had the FX Impact Compact and scope in a cool cust hard case.The other had the pellets and boxes for the scope, and documentation.
Tony also included a chronograph receipt tape and a grouping in a cool little pamphlet. Yeah, this speaks volumes and that group is real – let me tell you that right now.

In Summary

I’m writing this six months after getting the Mk2 Impact Compact and I was impressed then and still am now. They have now moved on to a “M3” and it’s getting good reviews with an even bigger plenum, twin transfer ports and improved ergnomics. At any rate, in the next post I’ll tell you more about my experiences hands on because there are things I like with my Mk.2 and things that I don’t.

Note, I have to buy all of my parts – nothing here was paid for by sponsors, etc. I do make a small amount if you click on an ad and buy something but that is it. You’re getting my real opinion on stuff.

If you find this post useful, please share the link on Facebook, with your friends, etc. Your support is much appreciated and if you have any feedback, please email me at in**@ro*********.com. Please note that for links to other websites, I may be paid via an affiliate program such as Avantlink, Impact, Amazon and eBay.