AK74 Rear Trunnion

[ezln]

Hey. I have a Bulgarian AK74 that has the rear trunnion placed about 1mm too far back, so when it fires, the front end of the dust cover blows upward. Does anyone know of a good fix for this, besides welding a shim on the trunnion? Thanks!

[acmech]

I made the same mistake building my first gun. I tack welded a shim on the rear trunion. Hardley noticable, but not something I'm proud of. I scratch built my receiver so I should have checked the top cover fit.

[ftierson]

One of the ones that I have is slightly too long between the rear sight base and the rear trunion too.

My temporary (but perhaps permanent) fix was to bend out the bottom rear of the receiver cover (lengthening the cover slightly) to fit more tightly. This has worked so well that I think that I'll consider the problem solved. The receiver cover still doesn't seat completely into the rear sight block at the front, but it's captured well enough that it doesn't become dislodged when firing the rifle. If you use this fix, keep in mind that the thin sheet steel of the receiver cover can be torn quite easily, so use care when bending the rear outward. I found that a large crescent wrench closed on the cover spreads the force out over enough area to solve most of this problem (always use the right tool for the right job :) ).

This problem occurred only because, when first starting the AK building quest, I put too much faith in the rivet hole receiver templates that are available. OOW receivers are often "too" long at the front if you simply place the front trunion flush with the front of the receiver. Then, when you rivet the rear trunion, the length between the two is a little too long. Now, I always rivet the trigger guard/mag catch to the receiver before anything else, and then place the front trunion to get a tight mag fit. With the OOW 5.45mm receiver, this almost always means that a small amount will need to be taken off the front of the receiver for a flush fit of trunion to receiver (and I don't mean this as a criticism of OOW either, because it's a lot easier to take material off than to add it on, if you know what I mean). Then, with the front trunion in place, use the receiver cover to place the rear trunion (which will usually be just about where you think that it should be from the side cut in the top rear side of the receiver).

Anyway, enough rambling on...

Bending the receiver cover should do it...

Forrest

[sportsnut]

Weld some material on the front of your dust cover, then file to fit.

[einheit 13]

Hey. I have a Bulgarian AK74 that has the rear trunnion placed about 1mm too far back, so when it fires, the front end of the dust cover blows upward. Does anyone know of a good fix for this, besides welding a shim on the trunnion? Thanks!

Did it by chance come from Military Gun Supply???