Category Archives: Gunsmithing

Posts that touch on gunsmithing topics such as improving function, finishes, changing parts, and anything else that alters a weapon

Good animation of an AK-47 operating

I’ve seen other animations in the past that didn’t get into as much detail as this one.  In this video you get a pretty good demo of how the various parts work during the firing and automated loading of the AK-47 but they got the trigger wrong, etc.  This one shows the disconnector and trigger hook operating in the right manner for example.  I’m posting it because I think it always helps to understand what is going on inside a firearm for when you want to tune it, figure out what might be going wrong, and so forth.

Two Rivers Arms Built Yugo M72B1

Once in a while I get to have fun.  For years I have worked with Two Rivers Arms making their grips so I knew they did a good job.  Well over a year ago, I bought two Apex M72B1 kits to have as prototypes but never had time to build them.  I must admit I have fun building rifles but the time just isn’t there any more.  So, given our new M72 handguards were almost ready, I called up Tim at Two Rivers and asked if they could build an M72B1 that looked like it came straight from the factory and that is exactly what they did.  Here are the amazing results of their efforts:

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Note, the following is our Yugo M70/M72 grip:

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Let me give you a quick run down of the parts you see above and a few you don’t:

  • Yugo M72B1 kit from Apex with a new Green Mountain barrel
  • Nodak Spud NDS-9 receiver
  • New virgin stock set from R-Guns
  • One of our Yugo M70 pistol grips
  • Tapco G2 FCG
  • RSA FCG retainer plate (I hate the shepherd hooks)
  • Real Yugo BHO Magazine

Two Rivers did the assembly, engraving, bluing and hooked me up with the right muzzle nut and cleaning rod.  This rifle looks simply amazing.  If you ever are looking for a builder, give them a shout … now if I can just afford one of their Tabuk DMRs some day 🙂  Tim, Shawn & Ed – thank you!!

Two Rivers Arms is at:  http://tworiversarms.com/ 

Our pistol grip is online at:  http://shop.roninsgrips.com/Yugoslavian-M70-M72-M85-M92-Grip-Yugo-M70-M72-M92.htm


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 Ronin’s Grips’ Vepr Furniture Set

Ronin’s Grips Vepr Furniture Installation Notes

Version 1.7  1/27/2014

First and foremost, please ensure your rifle is unloaded and a round is not in the chamber.  Please be safe!

In general, the urethane plastic we use for the buttstock and handguard will behave like hardwood when it is being cut.  Thus, if you choose to install something, follow the guidance for a wood stock in terms of hole sizes to drill, tools to use, etc.  Note, the plastic has very little give and forcing parts together will risk stress fractures.  Make sure they seat/fit in a square even manner.

The following are installation notes for each component of our Vepr rifle furniture system.  What you need to install will depend on what you purchased.

Buttstock

The buttstock is attached to the rifle’s rear trunnion via two #10×7/8” screws.  The urethane plastic we use is very hard and ideally the hole for the screw should be drilled with a #21 (0.1590”) drill.  Take care to ensure the stock is centered before locating and drilling each hole.

Tip:  If for some reason you need to drill a new hole, the old hole can be filled with quality epoxy cement and allowed to cure per the instructions of the glue. To fill a deep hole, either run the epoxy down the side or use something long and thin, such as a toothpick, to get the epoxy to the bottom.

For durability, use a longer setting high-strength epoxy as the quick 90-second, 5-minute and 10-minute epoxies are prone to “sugaring” or breaking down with constant jarring.  JB Quickweld, Brownell’s Acraglas (our recommendation) and DevCon industrial epoxies (such as “Plastic Steel”) are all good choices.  If you want to color the epoxy black, add a bit of black powdered tempera paint to the mix while stirring thoroughly.

Please note that if you buy the buttstock without a recoil pad, you must add one to protect the end of the stock from abrasion.

Optional Recoil Pad

The recoil pad is secured to the rear of the buttstock via two #10×3/4” screws.  Again, be sure to drill a hole first with the recoil pad centered on the stock.

If you want to blend the pad to the stock, put a thin film of black RTV silicone on the buttstock and use your finger to smooth the edge between the stock and the pad.  This is for looks only – the screws must still be used to secure the pad in place.  If you decide to do this, fit the pad first and have everything ready.  Then remove the pad, add the thin amount of RTV, put the pad back on, tighten the screws and then blend the silicone with your finger.

Handguard

There are two key things you need to know about the handguard:

First off, there is a special 13mm wide x 5mm thick spacer in the bag with the screws.  It must be used between the handguard and the barrel lug to get the angle correct.  The original Vepr screw is used and the special spacer is mandatory.  If you lose the spacer at some point down the road, stack 6mm washers from the hardware store to get the necessary space between the barrel and the handguard.

Second, with the spacer on the screw, swing the handguard into place but do not tighten the screw.  The Vepr handguard sometimes fits tightly and you don’t want to adjust the screw hole if the unit isn’t fully seated at the rear in the receiver.  Carefully remove the screw, leaving the spacer properly positioned and look down in the hole and check the alignment between with the screw hole in the forearm and the hole in the barrel lug.  You may need to use a circular file to carefully “slot” the handguard hole just a bit to get proper alignment.   It is very important that you make sure the handguard is fully seated to the rear before you make any changes. Take a little off and test over and over– go slow and don’t rush.  Use the oblong washer that came with the stock to reinforce the hole.  If the handguard does not rest squarely against the receiver you will risk the handguard cracking by the barrel lug as it will be placed under undue stress during firing.  So, take your time slot the hole as needed.

Care of the Handguard and Buttstock

The handguard and buttstock are made from our proprietary urethane plastic that is machinable.  This means you can drill, cut, sand, abrasive blast and so forth.  When we build the furniture, we sand to 180 grit and then use 80 grit AlOx blast media at 90 PSI to frost the plastic.

If something chips or gets scratched at some point in the future, sand with 80 grit, then 100-150, then 220, then 320 then 400.  Another option is to repair the scratched area and then abrasive blast after 150-180 grit sand paper is used.  When making the furniture, we use an abrasive blaster with 80 grit aluminum oxide media at 90-100PSI to create a non-slip surface.  After either sanding or blasting, you can apply a wax based finish as a “top coat”.  The recommended sealer is actually a beeswax blend developed for boots called “Sno-Seal” by ATSKO.  In general, you could use any wax based finish such as clear or black shoe polish, that is then buffed with a cloth.

 

Thank you for purchasing our furniture.  We truly hope you enjoy it.

 

ATF Opinion Letter on AR Pistols – Some Key Considerations

In this ATF letter, the author asked the ATF’s opinion on a number of great AR pistol related questions.  I am paraphrasing a few points I found important to help folks doing full text searches for opinions:

1) An AR lower receiver is neither pistol nor rifle until it is built the first time.  If you want to make a pistol, a lower receiver must *never* have been built in a rifle configuration.

2) AR pistols do not have a barrel length restriction.

3) AR handguards can be used on an AR pistol

4) An AR rifle and pistol can be in the same household — note, and this is a personal comment, what got a guy in trouble years ago was that he had only an AR rifle and a pistol upper with no lower to mount it on.  I don’t remember all of the details but the main thing here is that you never want it to look like the only reason you have a pistol/SBR upper is to put in on your AR that is legally classified as a rifle.

5)  Magpul angled fore grips (AFGs) are permissible on the bottom accessory/picatinny rail.

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I recommend people print and keep copies of letters just in case they need to show someone that some aspect of a weapon was “approved” by the ATF at some point.  Just bear in mind that ATF letters are not absolutes but it helps to have them handy if asked.  A state or local government may have their own more restrictive regulations as well so this may not mean AFGs are legal for everyone everywhere.

Legal Disclaimer:  I am not an attorney and am not giving legal advice.  I am just passing this information along and it is up to you to determine what you can/can’t do.

ATF letter stating that the Magpul AFG is legal for use on AR pistols

Please treat this as reference material only and not legal advice. The ATF does not always adhere to letters, states and local governments are doing their own thing and it’s hard to say what is acceptable or not just to be perfectly blunt. We live in interesting times unfortunately.

Folks, here is an ATF letter saying that an angled foregrip (AFG), such as Magpul’s models, can be used on an AR pistol.  This is the first time someone shared a definitive letter with me vs. hearsay.

12/14/2014 Update:  Here are scanned images of two different ATF letters saying AFGs can be used on AR pistols because they are not considered vertical grips:

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This is a second letter wherein they answer a number of good questions about AR pistols in general.  On page three is another comment that the AFG is allowed:

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The reason this matters is that a vertical foregrip is not legal without first registering the pistol as an “any other weapon” or AOW.  I recommend people print and keep copies of letters just in case they need to show someone that some aspect of a weapon was “approved” by the ATF at some point.  Just bear in mind that ATF letters are not absolutes but it helps to have them handy if asked.  A state or local government may have their own more restrictive regulations as well so this may not mean AFGs are legal for everyone everywhere.

Legal Disclaimer:  I am not an attorney and am not giving legal advice.  I am just passing this information along and it is up to you to determine what you can/can’t do.


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.


Sources For AR Parts

The following are all vendors of AR parts including barrels, handguards, triggers, magaziness and what have you that I use and recommend:

Beware no-name knock off websites selling generic import stuff. Some of the parts are counterfeit and not rated for firearms use.


What is a Ferrule on Yugo and AK Rifles?

A ferrule is a metal end cap found on some wood grips and handguards to protect the end grain of the wood from being hammered and splitting open.  They were used on different country’s weapons and are usually not interchangeable between countries.  For example, Bulgarian and Yugo ferrules are different.

Near and dear to me are the metal ferrules on Yugoslav / Zastava wood lower handguards.  The following photo shows a M92 lower and the black metal cap is the ferrule.  This ferrule does not fit everything Yugo – just the M70, M85/92, and M77.  The M72 and M76 are unique sizes.

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You have three options when you need a ferrule:  1) Find a used one and this is real hard – try posting in the Marketplace of http://www.akfiles.com and see if they have one.  2) Buy a replica ferrule from us or 3) Simply pry the old ferrule off, put it on the new handguard and the squeeze the tabs shut again with a pair of pliers.

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Note if you are putting it on one of our plastic handguards either just set it on it with the ears closed or glue it in place.  Absolutely do not try to squeeze the ears shut — the little metal divots will not dig into our plastic and you risk snapping the handguard tabs.  Again, either slide it on or glue it in place with something like rubber glue or Goop that you can later remove if you want.  Epoxy works too but it is pretty permanent.

For example, I just slid the ferrule on the M70 bulged handguard in the next photo.

We manufacture ferrules that fit the Yugo/Zastava M70, M77, M85 and M92 lower handguards. Note, they are specific to those models and will not fit other nationalities or models.

Click here to visit our store with the ferrules for sale.


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.




What the M92 Looks Like After All the Mods

This shows what the M92 looks like today.  I haven’t had time to go to the range yet but the “feel” is fantastic in terms of weight, balance and length. CNC Warrior nailed the folding arm brace.  Wow – how cool it is!

Here is a list of the modifications made:

  1. CNC Warrior Folding Arm Brace
  2. CNC Warrior 4 Piece Brake
  3. CNC Warrior Detent Pin
  4. CNC Warrior Picatinny Rail Scope Mount
  5. Ronin’s Grips M92 Ferrule Cut Handguard Set
  6. Ronin’s Grips Bulgy ARM-9 Pistol Grip
  7. Ronin’s Grips M92 Dust Cover Quick Takedown Pin
  8. Vortex Sparc Red Dot with the Low Mount
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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.