Category Archives: Firearms Building and Gunsmithing

How to build and/or gunsmith on certain platforms.

Assembling an AR Lower – Step 3 of 11: Installing the Bolt Catch Assembly

In this step, I’ll install the bolt catch.  This is the part that catches the bolt when the magazine is empty or the operator wants to lock the weapon open.  In terms of risk, this step has probably caused more blemished receivers than any other.  What I hope to show you is a method to minimize that.

The assembly is made up of the catch itself, a cross pin that secures it in the receiver, a spring and the bolt catch buffer.  In this post, I am actually installing a Strike Industries bolt catch.  I like to have a slightly larger paddle to operate the catch and Strike model is a nice size.  If you ever want a giant paddle, Wilson makes one but it is just too big for my taste.

Here is the catch, it’s roll pin directly underneath and then the spring and detent to the right.

 

Where we are working on the receiver is right here – just above the mag catch:

The spring followed by the detent go down in the hole just above the magazine catch. The bolt catch is then inserted in the slot and the pin secures it. This is when you wonder if a third arm is needed 🙂

Now, this step is really risky.  One slip and you will mar your receiver so take a minute and put some duct tape on just in case.  I like duct tape because it is thick and sticks really well.  I’ve used other types of tape in the past and it really is just cheap insurance.  If you do this and what you use is up to you.  You are mainly worried about the receiver, to the right of the humps/lobes where the catch is going to be installed.

If you want to lower your risk of scratching your receiver, put a heavy tape around the assembly for protection. I’d recommend a duct tape – I’m using Gorilla Tape in this photo.

Now I use three punches for this.  I bought two rubber coated mag catch punches from Wheeler.  They work but I wish they were longer and you still need a third to make it easy.  Let me explain a bit more.  The Wheeler punches are half circle designs which gives you better clearance but I still use my long Astro Pneumatics 1/8″ punch to reach down and drive the pin the rest of the way in. Like I said though, you do need three punches for this.

The two black punches make up the Wheeler 710906 bolt catch tools and I literally use them with every build. Above them is a longer roll pin punch that I use to finish the install. I wish the Wheeler punches were about an inch longer and they would be perfect for me but note I do use them on every build.
The Wheeler punches are must haves for three reasons – they are flat on one side to let you get in closer to the receiver, they are rubber coated to protect the finish and you have both the 3/32″

Ok, so first take the roll pin starter punch and install the pin on the right side part way.  By getting it started you have less to try and mess with as the assembly comes together.  See how the punch is right next to the receiver?  You need to lightly tap this with a small hammer to drive it in while not hitting your receiver – this is why the tape is cheap insurance.

The Wheeler starter punch lets you easily begin the pin with zero drama and swearing.

I like to put a dab of grease in the hole to hold everything gently in place.  This is not a normal step and just something I do.  You then insert the spring first and the buffer on top.  You’ll notice with the AR design that a spring always has a detent or buffer between it and a moving surface to protect the spring.

I put a dab of grease in the hole to hold the spring and detent in place.

  Next, I use the roll pin punch from Wheeler to align bolt catch and hold it in place so the roll pin can be driven further in.  If you do not use something to align the catch holes for the pin you will drive yourself nuts.  Another option is to use a 3/32 drill bit’s smooth end to help line things up by inserting it through the front hump.

Use the pin punch to keep the catch properly positioned as you drive the roll pin through. Just short of bottoming out the starter punch, use a pin punch to drive the pin in the rest of the way.

Next, you need to use the roll pin punch and a small hammer to drive the pin the rest of the way in.  You can use the Wheeler block to hold the receiver or whatever works for you. Having a firm support makes it much easier.  My Astro Pneumatic roll ping punches are long.  My 1/8″ punch is 7″ long so I would recommend looking for something like that so you can clear the receiver when you are hammering the pin all the way in.  I don’t think the Astro set I have is made any longer because I could not find it on Google to share with you.  I use my Tekton punches.

See how much longer the Astro Pneumatics roll pin punch is? This lets me reach in and easily drive the roll pin in the final bit of the way. I can do the same with my Tekton gunsmith set’s punches.

With that you are done.  You can function test the unit by pushing on the top paddle.  You should feel the spring compress and release as you rock the catch back and forth.


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AR Parts Sources

There are a lot of reputable AR parts vendors online but beware of eBay and bargain basement dealers that sell airsoft parts and tell you they will stand up to firearm use – they will not. At any rate, here are my top sources of AR parts:



Assembling an AR Lower – Step 2 of 11: Installing the Trigger Guard Assembly

The second step is to install the trigger guard.  Now I do not use the kind with a detent that allows you to open the trigger guard.  I prefer aluminum trigger guards from either Magpul or Brownells.  The one you see here is from Brownells and is made from billet 7075 aluminum.  I like how it is slightly oversized for gloves and Brownells prices it quite reasonably at $8.47. The front is threaded with a set screw and the rear has a roll pin – they include both in the package.  A polymer Magpul unit came with the lower build kit and I just put it in my box of spare parts.

Take a minute and check the fit.  The threaded part goes forward and the hole that goes all the way through to the rear.   Just ensure it is going to line up appropriately.

I like to first install the front set screw to help line everything up.  Just use a quality allen wrench – I have been burned with cheap allen wrenches that round the socket so now I pretty much stick with Bondhus and Eklind though there are probably many other good enough brands out there.  I snug the set screw down but do not go crazy torquing it in.  Bear in mind you are threading a small screw into aluminum and that allen key is giving you quite a bit of leverage.

Once that front screw is in and the trigger guard is better held in position, it is time to install the rear roll pin.  Now you have a number of options to install the rear pin and I am going to tell you about the two I use:

Option one, use a starter and roll pin punch to drive in the roll pin.  Now there is a real important thing you need to do – be sure you use a block to support the lower “ear” of the receiver or you may snap it off.  If it breaks off, you just ruined the receiver – game over.  I use a Wheeler block to support the receiver and you can use just about anything – over the years I have used generic gunsmithing blocks and even pieces of wood. For the last 2-3 years I’ve used the Wheeler block and like it.

Don’t try to use a generic punch.  I like to use a Squirrel Daddy roll pin starter to get the first part of the pin installed and then an Astro Pneumatics 1/8″ roll pin punch to hammer it in the rest of the way.  Of course you can use whatever brands you want but the bottom line is that you need to line the pin up vertically to drive it straight in and you must be careful not to slip and mar your receiver.  This is why using the correct punches matter.  The starter punch gives you a lot of control and by using the roll pin punch, you can keep your punch on the pin.  Because of my tremor, I am not very good with hammers and punches but can do this provided I use the two types of punches mentioned.

The Wheeler 156945 bench block does a good job helping you both hold and support work.  You want the “ears” on the receiver to be supported.  There are plenty of stories of guys not supporting the ears, trying to tap in the roll pin that holds the trigger guard in place and then breaking off an ear.  Whether you use the Wheeler block or even a piece of wood – be sure to support the ears.

Note how nicely the Wheeler 156945 bench block supports the AR lower.
This is a roll pin starter punch. This one is made by Squirrel Daddy.

Option two:  Wheeler Engineering makes a nice simple tool to install or remove that roll pin.  Boy does it make it easy and this is my preferred method.  The little tool is super simple – it has two pins that fit into the end of the screw.  A long one for removing the pin and a short one for installing the roll pin.  You just line things up and then tighten the screw.  The pin goes into the hole in a very controlled manner and your finish is protected.  Stop once your pin is flush with the receiver.

Other options:  I have seen guys use pliers with the jaws wrapped in tape, modified C-clamps, and more.  You can Google around or search on Youtube to see a variety of approaches.


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.



AR Parts Sources

There are a lot of reputable AR parts vendors online but beware of eBay and bargain basement dealers that sell airsoft parts and tell you they will stand up to firearm use – they will not. At any rate, here are my top sources of AR parts:



Assembling an AR Lower – Step 1 of 11: Installing the Magazine Catch Assembly

Just a quick note – when you get a bare receiver, you are literally getting a chunk of aluminum with nothing installed.  I really like Palmetto State Armory (PSA) lower build kits and they sell them with different types of components such as just the basics for rifles, for pistols, Magpul furniture, etc.  What I like is that the machining is very good and I think they have some of the best Mil-Spec basic triggers that aren’t gritty.  I’ve used Anderson and other brands of build kits and just think the PSA kits are superior.  Bear in mind that I say this as a customer – nobody paid me to tell you this.

With that said, let’s start building.  You’ll notice on any AR magazine on the right side there is a rectangular notch.  This is where the magazine catch engages to hold it in place.  Okay, so the first step is to install the magazine catch assembly.  It’s made up of the “L” shaped catch itself, the mag catch spring and the magazine button.

Now I grease everything that slides with Tetra Gun Grease.  Tetra has worked well for me but I also know guys who use all kinds of greases.  As a rule of thumb, if it slides, apply grease.  It it rotates  then apply oil.  So grease the shaft and insert it into the round hole on the right end of the recessed area for it on the right side of the receiver.  Note, be careful when installing the catch or you may scratch your receiver.

When you turn it over you will see the threaded end of the shaft and you put the spring down over it.

Next, you will screw the magazine button onto the threaded shaft.  Before you do, look at the button.  You should see that one end is smooth (that is the bottom) and the other has grooves (that is the top).  Carefully start screwing the button on but stop before you get near the receiver so you don’t scratch anything. Push the button in, and then turn the long lever arm to continue threading the shaft into the button.  Now stop before the lever arm scratches the receiver.

To screw the catch in the rest of the way you need to push the bullet button in all the way so the catch sticks out as far as it can on the other side so the lever arm can clear the parts of the receiver as the button is screwed on.  At this point, I use a small pusher tool made from plastic to push the button in even further so I can keep turning the lever arm until the screw is relatively flush with the top of the button.  Note, before I had the tool I would use a wood dowel.  Just use something non-metallic to protect the finish.  There is a model of the tool shaped just like the oval button but I don’t know where mine went so I used a takedown tool and got the job done 🙂

The catch is now installed.  To function test, push the magazine button.  You should feel spring resistance and see the magazine catch’s lever arm push out.  When you ease off the button, the lever arm should smoothly go back into place.


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.



AR Parts Sources

There are a lot of reputable AR parts vendors online but beware of eBay and bargain basement dealers that sell airsoft parts and tell you they will stand up to firearm use – they will not. At any rate, here are my top sources of AR parts:



Assembling an AR Lower – Like Legos for Men with Special Comments on Pistol Builds

I have to admit that I like a lot of different firearms including both AK and AR platforms.  So I am not purely an AK fan though my business is largely built around that.  I have owned many, many different ARs over the years including tactical, DMR, snipers, pistols and flat out range toys.  I don’t have much free time any longer so the AR platform gives me a chance to tinker with different combinations and see what I like.

At the heart of the AR is a lower-receiver that can be made by just about anyone as long as it is Mil-Spec.  Now this is critical. Not all receivers are as accurate as they claim to be with their tolerances, hole positions and what not so ask around.  I’ve had very good luck with Anderson (my go to brand for several years now), Palmetto State Armory (PSA), Spikes and Del-ton.  I’ve not had a single problem with any of these brands.  You may not have as much luck with “Uncle Bob’s Lowers made in Podunk Nowhere” so just start with a good foundation.

For the two AR pistols that I will be assembling for the upcoming blog posts, I will be using Anderson lower receivers.

Assembling an AR for a rifle or a pistol is almost identical until you get to the gas tube.  At that point a pistol must use a pistol tube and a rifle will use whatever tube you wish.  I’ll point that out again in post #9.

I am not a lawyer and the following should not be construed as legal advice.  I’m just trying to explain my understanding on how to build an AR pistol legally:

One important item for guys making pistols, to be legal, the receivers must be transferred to use as receivers.  Your FFL must NOT transfer the receiver as a rifle.  There is an FFL notice that once a receiver is built as a rifle, it is a rifle.  If you change it into a pistol, then you are making a short-barreled rifle (SBR) that must be registered.  Oddly enough, you can build a receiver as a pistol and then convert it to a rifle.  [Click here for a link to the ATF letter]

My recommendation is to always take photos of the pistols built appropriately so you can show the paper trail of a receiver transfer from your FFL through to a built pistol.

Also, there is another issue to avoid – do not buy pistol-length uppers (meaning uppers with barrels shorter than 16″) and having them sit around without a pistol receiver waiting.  Buy the receiver first, then corresponding upper and put them together.  Why you might ask?  The concern is something known as “constructive intent”.  You do not want the ATF or others in law enforcement to assume you only have that SBR/pistol upper to put on one of your rifles.  That requires paper work and fees in order to have a legal SBR.  You absolutely can’t just put a sub-16″ barrel on a regular rifle – it will be illegal.  [Click here for the ATF letter about SBRs]

The ATF has ruled that braces do not make a pistol into a rifle.  I have carpal tunnel and can’t hold a heavy pistol so this is good news for me.  So, I bought my Anderson lowers first, my lower pistol build kits from PSA and then an 7.5″ upper from PSA and a 10.5″ upper from Ghost Rifles.  The blog posts that follow document my journey building these two AR pistols.


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.



AR Parts Sources

There are a lot of reputable AR parts vendors online but beware of eBay and bargain basement dealers that sell airsoft parts and tell you they will stand up to firearm use – they will not. At any rate, here are my top sources of AR parts:


Video: How to build an AK-47, AK-74, AKM. Complete video tutorial by bfgmovies — Best Rivet and Virgin Barrel Build Video I’ve Seen!

Folks, once in a while I find out a snap judgement I made is very wrong.  I was watching AK Build videos on Youtube and ran across this video with a very young man with long hair and anime shirt sitting down to talk about building an AK.  I almost snorted because it must be some kind of a gag.  Within the first five minutes I realized this young man was very knowledgeable, articulate and very capable at demonstrating how to build an AK.  I was floored.  I almost missed this because my snap judgement was so off.  Wow.

This young man assembled a 55:59 long video showing you how to do an AK build with a manufactured receiver using a virgin barrel and he explains things along the way.  To give you an idea of the quality, this video was posted in May 2013, has had 104,441 views, 1,114 thumbs up approvals and only 74 thumbs down.  Folks, that is remarkable.

I am sharing a number of photos from the video to get you to realize this is really good.  He steps you through everything including aligning the blocks on the barrels, the barrel to the receiver, drilling pin holes, headspacing, setting rivets and then final assembly, including installation of the fire control group (FCG), function testing, installing the furniture, and finally winding up with applying Alumahyde II from Brownells as the finish.  I’d honestly say it is the best AK build video I have seen thus far that takes you all the way through the process.  This is really worth your time.

P.S.  The music and anime at the end is a nice touch 🙂

If you want to learn more, check out these other two video by bfgmovies:


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.



ATF letter stating you can build an AR pistol from a receiver transferred as such and never assembled as a rifle

Okay, I posted a couple of ATF letters and a guy sent me a message asking if I had the letter specifying that an AR pistol can be built from an AR receiver that was transferred as a receiver and never assembled as a rifle.  It just so happens I did save that one back when I built a couple of AR pistols a few years back.  I like to have the letters of anything someone may ask about and keep them in my case with the weapon when I take it shooting.  At any rate, here is the ATF letter in case anyone else needs it:

Please note that I am not a lawyer and this should not be construed as legal advice.

 


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.



Remington 870 and Winchester 1200 Riot Shotguns

Ran across these photos of two riot shotguns I built – a Winchester 1200 I bought new in the early 1980s and a Remington 870 Express I got a good deal on from Gander Mountain in the early 2000s.  One thing I learned is that the Blackhawk recoil reducing stocks really make a difference.

 

To be honest, I think Remington makes a lot cheaper guns than they used to and their quality has suffered.  Some years back I picked up a Remington 870 express in great shape but one thing that drove me nuts was that the little orange plastic follower would spring out and jam the action.  I did some quick digging and found a machined aluminum replacement that I installed and never had a problem since.

Also, from a pure “keep it simple” angle, I have since stopped installing anything on a tactical shotgun other than a light.  It took to long to turn on the red dot plus worries around battery life, was it still zeroed, etc.

For lights and lasers, I really like the Streamlights.  I use a TLR-1 300 lumen LED light on my home defense 870 to this day.  They are rugged, simple, easy to operate and durable.  Having had a ton of cheap Chinese imports fail over the years, I only use proven lights and lasers on critical firearms.  To save on the CR-123 batteries, read my post on that topic.

The red fiber optic sight really worked out better than I thought.  It made target acquisition fast.  I eventually ditched the red dot optic, installed a side saddle shell holder and used just that sight.

The flashlight on the Winchester was a Hellfighter with a xenon bulb.  It was ok but I would only buy LEDs going forward and my preferences are Streamlight or Surefire.

The Blackhawk recoil reducing stocks do a very good job but make sure you buy the right model.  They sell stocks both with and without the recoil reduction system.  Also make sure you get the right model – they make them for Winchester and Mossberg.  The following is an automated search from eBay so you need to double check the product and that the buyer has plenty of trades and good feedback.


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.



How to Install a Flat’s Lower Receiver Rails So They Align With The Front Trunnion

I heat treat the lower rails before I install them.  The best way I found to align the lower rails in a flat so they were both parallel with the upper rail and aligned with the trunnion was to use a drill bits of the proper size to locate the lower rail and I would then clamp the lower rail in place prior to spot welding.  This is one of those things where you want to check and double-check prior to and after each weld to make sure nothing shifted on you.

I use a Harbor Freight #45689 115 Volt spot welder with AK-Builder upper replacement tong and also tips.  It’s lasted me through quite a few builds over the years and is still going strong.  The tong makes it way easier to reach in and make the weld and the tips make the spot weld look a lot more like the real ones.  I have had to replace the tips once so far, just FYI.  You need to keep them clean to be most effective.

For beginners, there is no way to tell you how long to clamp and trigger the current for – many factors can affect how long it takes to heat the steel up enough for the two pieces of sheet metal to weld together.  You need to practice and you’ll notice the color, sound of the welder. the amount of time it takes to get a good weld and especially the feel of the clamps as they come together during the weld.  With practice you’ll feel when you have a good weld especially but it all adds up but you need to actually do it to learn.

Get scrap metal of about the same thickness to practice with.  AKM receivers are 1mm thick.  18 gauge is 1.02mm so it is good to practice with and old scrap receiver stubs are another.  With your first practice weld, go long and let the pieces really melt together so you can see.  You want to burn a hole to understand how long it takes, the sound and the feel of the tongs.  Then practice with less amounts of time until you find the sweet spot.  These welds should be pretty strong and not pull apart easy.  I do more spot welds than most and some guys look at photos of the rifle they are building and try to approximate the count and location, which is just fine.  One thing, if you do heat treat your rails before hand like I do, be careful you do not get the tongs up against the ejector and ruin the heat treat.  I’ve done it and the tell tale sign is that the ejector will be discolored from the heat.  If you do make this mistake you will need to heat treat the tip while it is in the receiver or else it will definitely peen over and be deformed in its softened state.  By the way, the steel should be relatively clean also and not have tons of grease or other contaminants on it either that might inhibit a good weld.

Just double check alignment very carefully before you spot weld and also that your welder’s tong does not get against the ejector and ruin the heat treat – assuming you did that before installation.

I hope this helps you out!


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.