Two Rivers Arms recently built a Yugo M76 8mm designated marksman’s rifle for me. I’ve wanted one for years and it was a long but worthwhile wait until it arrived. So, once Tim called and said it was almost ready, I started reading up in earnest and watching videos as well.
That’s where Ian McCollum of Forgotten Weapons enters in. I am a fan of Ian at Forgotten Weapons and both subscribe to his Youtube channel and support him via Patreon. Ian published a video of him using a Yugo M76, or as it is formally known, a Zastava M76, in a 2-Gun match. It’s a quick fun watch to see Ian swinging around the big rifle.
This is John’s Zastava O-PAP. You can tell because it notably does not have the flip up grenade sign on the gas block. It definitely has clean lines and you can see the bulged trunnion that is another clear indicator that this is the heavier duty O-PAP and not the N-PAP.
John’s rifle has one of our Yugo M70 grips on it. The Yugoslavians and Zastava saved money by using this unique ergonomic grip on a number of their models including the various favors of the M70, M72, M85, and M92.
John’s grip is colored black and has our matte/blasted finish for a sure “hold” even when wet.
Okay, I had them both out to shoot photos so I had to take some side by side photos. In case you want to read the blog posts about each rifle, click here for the Yugo M72 Carbine or here for the Vepr FM-AK47-21.
This video covers handguns, rifles, submachine guns, light machine guns and so forth used by Yugoslavia from 1924 to 1999. It does not have anyone talking, just music. What it does have that is interesting is tons of photos of various weapons and in some cases even footage showing use. I watched in interest the parts with the AK-related rifles such as the M70, M72, M85, M92 and so on plus the M93 Black Arrow that I’ve always found interesting. I got to hold and inspect one at Ohio Rapid Fire years ago.
At any rate, it’s interesting and worth 28 minutes to watch what the author assembled:
I like Zastava firearms – notably their rifles – M70, M72, M67, M77, and M92. I’ve owned variants of all of those at one time or another and think highly of the designs and the quality of manufacturing. I ran across this short 160 year commemorative video released in 2015 and thought I would share it:
Let me open this article with a comment for people new to building AKs – the best proven method is to use rivets. The Soviets did a lot of testing and the best mechanical join of the forged trunnions to sheet metal was a mechanical rivet. To this day, all commercial and military AKs are built using rivets. In my journeys, I have built AKs using welds, screws and rivets – all have pros and cons. What would I build an AK with that I care about? The answer is easy – rivets. This blog post documents my building a prototype using screws. Has it held up to casual non-military non-full-auto use? Yes. What would I recommend to you to build your AK? The answer is rivets.
In a previous post I described taking a milled stub and welding it to a sheet metal receiver. Another approach is to drill, tape and use alloy screws. So, let’s talk about that a bit. I did this build back in 2010 also. I actually still have the rifle and it’s one of my most reliable AKs. It takes about any ammo I stuff in it and I don’t recall ever having any issues.
For those of you who are wondering why I didn’t do rivets – I was bored and wanted to try something different plus this is a range gun and not something mission critical. Here we are 7 years later and it’s still doing fine – no cracks, no loose screws … but it isn’t stressed either. When in doubt, do rivets or a milled gun.
Also, bear in mind that the front trunnion was made from the milled receiver stub so screws made it real easy.
In terms of this build, I milled the trunnion down the same as I did for the weld build. I used my Hungarian AMD trunnion as an approximate guide for locating the holes and used two #10 screws for the front top and a 1/4″ for the rear. In both cases, I opted for national fine. 10-32 and 1/4-28. So, for 10-32, I used a #21 drill bit to make the hole and for the 1/4-28, I used a #3.
For drill locating and drilling the receiver holes, I used the AK-Builder trunnion rivet locating jig. You just put the trunnion on the jig, locate the hole, slide the receiver on and drill the hole.
Now for tapping, being square is a good idea. I squared my table to the drill press’s chuck and used it to hold the tap. I use Tap Magic cutting fluid to lubricate everything.
For the screws, I used alloy button heads and secured them with red thread locker. I reached in with a Dremel and ground down protruding screws.
So there’s the front. I used an air riveter to do the trigger guard.
I miss building AKs – I never have the time any more. At rate, some years back I wound up with two Yugo M70 front milled stubs, and then decided to convert the rifle to a stamped receiver because I liked working with AK-Builder flats. So, in the spirit of trying something new, I decided to convert a stub to a trunnion and plug weld it in place vs. trying to machine the rivet seats inside.
Yes, I’ve heard tons of people say not to weld them together and that rivets are better. Yes, rivets are better and I have done many of them. Have I ever had problems with a weld build where I filled the holes I drilled with plugs, stayed away from the locking lugs and was careful with the heat? No, I have not had any problems. I have an AMD-65 with tons of rounds through it that still runs fine. My thinking is that I am not firing full auto, not using grenades, don’t use this in combat … I’m not really stressing it. What would I use for a reliable build vs. a test like this? I’d use rivets.
Why the big caveat in the previous paragraph – I get one or two emails a year from a purist telling me that what I did was evil, that I am a clueless half-wit, etc. Folks, innovation happens by trying new things. I have built more AKs than most – using rivets mainly because they do work best. There are a ton of reasons why rivets are best for joining forged blocks to sheet metal.
In terms of welds, do I understand the risk of destroying the heat treat in the locking lug area, the risk of causing embrittlement around the plug welds, that the Soviets explored this and dropped the idea due to cracking? Yes, I do and tried it anyway because I wanted to explore how to compensate. So, don’t send me hate mail me because I will not bother responding. When I first shared this, three guys immediately sent me hate mails and unfriended me – I did not lose sleep about it.
If you want to try and experiment, go for it. Should you do this with an AK build that you want to be historically accurate or plan to use heavily perhaps even under full auto, then the answer is “no – don’t do it”.
The build I am sharing photos of was done in 2009. I found the photos and thought you might like to see them.
Here are the front stubs.
When you look at the front stub, you can see readily hiw it could become a trunnion.
Here’s a Hungarian AMD trunnion next to it.
Here are the stubs from a couple of angles. I already used my bandsaw to cut the top one
Ok, time to make some chips. It’s secured an I’m milling the OD under the top shelf of the trunnion that sticks out over the receiver:
I didn’t have anything to cut the slot with for my mill so I clamped a straight edge and then ran a Dremel wheel down it over and over until I got the depth and width needed for the stamped receiver to to slide into:
My theory was that by drilling holes and filling them via plug welds that I could lock the receiver into place. Thus, I drilled holes for the plug welds both in the stamped receiver and into the newly made trunnion:
The plug welds were done with a Harbor Freight 220V MIG running ArCo2 gas and .030 wire. I let it cool down after each weld and was careful not to pour on a ton of heat. Notice the relatively big weld area to distribute the load.
I then sanded it all down with a flap sander. The back was just a regular M72 rear trunnion that I found at R-Guns. I never had problems with cracking, etc. The experiment seemed to work for a casual use semi-automatic rifle.
That’s all I have as far as photos go. I hope maybe it gives you some ideas.
Writing this makes me wish I had time to build another AK but it’s back to our grips and handguards 🙂
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.
