AMD-65 troubleshooting

[Vintovka]

To start, I've had this AMD-65 since December of 2010. I've put a lot of rounds through it. My low estimate (counting just cases of 7.62x39 purchased, not counting the many times I've bought 2-3 boxes from Walmart or a gun shop) is 9,000 rounds. This is an absolutely fantastically reliable and durable firearm and this problem is almost certainly regular wear and tear; not any sort of quality issue or defect. It's one of the TGI guns with the Hungarian receiver and Hungarian barrel.

That said, I was shooting it last weekend and had an issue. I was about halfway through my first 30 round magazine and the dust cover popped off. I looked inside the receiver, saw no obvious issues, worked the charging handle a couple of times, and re installed the dust cover thinking that maybe I just didn't fully secure it after cleaning it the last time I shot.

I started shooting again, and a few rounds later, it popped off again. It was definitely totally secure and properly installed before that though. I put it back on, tried a few more shots, and noticed the bolt carrier getting hung up. It would go all the way back to the rear trunion, but would hesitate before going back into battery. I removed the magazine and racked the charging handle. The bolt stayed in the rear position and needed a pretty decent whack to get it to go forward.

So, the bolt carrier is really getting hung up in the back of the receiver and it is causing the dust cover to pop off when fired. Is this a sign of a worn out recoil spring? Would getting a new recoil spring solve this? I can't seem to put together any other answer than that. Thanks for your help.

https://fbcdn-sphotos-a-a.akamaihd.net/hphotos-ak-prn1/528504_448753968471483_1792855941_n.jpg

[Vintovka]

A quick update; I was just looking at it again, and determined that the bolt carrier hangs up much more severely with the dust cover installed than it does with the dust cover removed. Could it be a dust cover problem? A combination recoil spring/dust cover problem? This gun has been just about 100% perfect for the past 9,000 rounds, and nothing seems to be misaligned or deformed.

[Walleye]

Replace the recoil spring and that will most likely fix it. It's a cheap part costing 5-10 bucks.

[Vintovka]

Are regular AKM recoil springs and AMD-65 recoil springs interchangeable, or do I need to buy an AMD-specific recoil spring?

[Vintovka]

I needed a couple other things from Apex anyway, so I threw in an AMD recoil spring.

[eodinert]

I shot rifle grenades off of an AK without a gas shutoff one time, and the first sign that it was a bad idea was the top cover started popping off. In this case, the bolt carrier group was battering the rear trunnion because of the rifle grenades, and stretching the receiver. If your rear trunnion isn't loose, and the rivets don't show any signs of movement, I would scratch that off the list.

Sometimes with AKs when the bolt carrier recoils to the takedown slots in the top rails, pressure from the hammer on the bottom of the bolt carrier will push the BCG up and out of the tracks on the top of the receiver. In my experience, usually this happens on a build with a receiver with the take down slots too far forward. I had one build that had this problem, and the installation of a tubular style recoil assembly cured it (a standard AKM recoil spring will work). Some folks might say to throw a 'recoil buffer' in there, as it will keep the bolt from traveling to the rear of the receiver. In my experience these things cause more problems than they solve.

As to the top cover itself, I would take the bolt carrier group out, and fit the top cover by itself. If the front of the top cover pops out of the front sight block when I pull the top cover to the rear of the slot in the back, I'd fit a new one.

It's odd that it's doing this after 9k rounds. Have you swapped any trigger parts out? Also, I'm wondering if there isn't any wear on the sear engagement, letting the hammer sit up higher and pressing against the bolt carrier group.