Milled Yugo converted to Stamped Receiver
I built this Yugo by grinding down the trunnions and essentially manufacturing the front and rear trunnion from the leftover receiver stubs. The idea is not mine: I first read about it in a post by Al (bigmegina) somewhere on gun boards. A cheap angle grinder from Harbor Freight was used for the grinding. Going slowly, it took me about an evening per trunnion to get them all the right size -- but I work really slowly.
Scroll all the way down for the detail instructions and pictures. Yes I ground the living daylights out of them but in all, after you grind them and drill the holes for your screws or rivets, the build is just like any other stamped AK build!
Things I especially liked about reusing both trunnions is that I got to use the original buttstock (instead of replacing it with an AKM-style) and the sling swivel is mounted in the side of the receiver instead of on the buttstock. Cool.
See the heat treating marks?
The receiver on this build is a ak-buildler blank, did not have pre-drilled holes (they would not have worked with the conversion). The blank was bent using a DPH Arms bending jig in a 12 ton HF press.
Close-up Pictures and Build Steps
- Remove rivets from the trigger guard and separate the trigger guard from the rear receiver stub
- Inspect the receiver stubs. Where the receiver was cut, there are some bubbly edges, we will cut that part off.
- Cut the front receiver stub to the overall length of 2 7/16 inches with a dremel. You want to leave the two guide ramps which guide the bolt to lock into the trunnion.
- Score a line on each side of the front receiver stub using the following dimensions. You will be grinding the stub below the line so that the stub fits inside a stamped receiver. You will leave the metal above the score lines alone. It helps to use an existing stamped receiver or a bent blank to help you score the lines. On the graphic below, the score lines are red:
- Here are the receiver stubs, the front one has the grind boundaries scored on it:
- Using our 4 1/2" angle grinder, take off equal amount of metal from both sides of the receiver stub until it fits inside the new, stamped receiver.
Will look approximately like this:
On this photo you can see the tabs from the sling swivel, which, on a Yugo, is attached through a slit in the left side of the receiver. On this photo the rear receiver stub which is now trunnion has already been installed in the stamped receiver:
- On the receiver, mark where the screw (or rivet) holes should be. If you did not pull the barrel, you are using screws.
- Insert the receiver stubs into the stamped receiver. Drill the holes through the stamped metal receiver but only score the holes in the stubs.
- For the lower hole in the front receiver stub and the holes in the rear stub, you can just drill them. For the four front holes, if you did not pull the barrel, drill no deeper than 3/16". You will need the bottoming tap to tap these holes properly.
- You now have essentially manufactured the trunnions for your build. Proceed the same way as with any other stamped build.