"Bolt-over" failure to feed in AK action

[WeedWhacker]

I've got a rifle with an AK-type action which is jamming often. The short version of the story is that it appears as though the magazine is sitting about two-four millimeters too low at the rear, so that every so often (1-4 times per mag), the bolt will miss the rear of the next round and drag the round out of the magazine by the force applied to the middle of the cartidge case, causing a jam with the round pinched with the bullet nose just inside the chamber at an angle, with the bolt pinching the middle of the cartridge. This happens with all the mags I've tried, both new and old, 25 and 10 rounders.

The whole magazine attachment bit seems to be part of the receiver (at the front) and part of the trigger group/trigger guard (at the rear). The problem seems like it would be resolved if I could "tighten up" the connections at the AK-style mag release, so that the mag catch would be closer to the bottom of the reseiver... but it looks to be rivited in place without any way to modify (or remove, for that matter) it.

What options am I looking at to help improve the reliability here? What other problems might I be overlooking?

 

[model 649]

Just took a look at mine. If it were me, I'd compare it to one that works on another gun to see if there is any difference. It might be a simple matter of replacing yours with a good one. If the length is the same I'd go ahead and add metal (TiG) to the top edge and file to fit. Can you grab hold of the mag when it's in the gun and pivot it any further into the receiver at the rear? It shouldn't rise more than maybe a mil and a half. I also wonder if the front is too high, causing the rear to be too low? That might be as easy to fix as a few licks with a file on the mag's front hook. The length of my mag catch is 35.5mm from the center of the bottom radius to the flat top edge that contacts the mag. The distance of the top edge to the center of it's rivet is 15mm. If I stand the mag release up parallel to the trigger guard and measure the gap between the top of the release and the bottom of the receiver, I get 4mm. My gun works fine with this set-up. If you need to add metal to the mag release,any TiGger can do it. If you can't find anyone, I'll do it for the cost of postage. The part'll need refinishing afterward (or not, were it me ). Hope this helps ya.
Josh

 

[WeedWhacker]

Well, I took my rifle out to the range and shot 250 rounds through her - not one problem, not with any of the magazines, either. I wonder what I was doing to cause the problem... I probably should have mentioned that the problem with the "bolt-over" jamming only happened when I was manually working the slide. I'd pull it back as far as it would go, hold it with my index finger and thumb, then let go so I wouldn't ride it forward. The rifle is a Hadar II rebuilt to Galil 329 specs, by the way. Great fun.

As for the magzines, mine fit a "little loose". I can wiggle them around and they have a play of, say, no more than two millimeters, if that, when the bottom rear corner of an empty mag is pushed up under an open bolt (so no pressure from mag or bolt). With cartridges in the mag or with the bolt closed, there's almost no play; maybe a half millimeter, if any. Good fit, but I wonder if it could be better to, maybe, elmiminate that last bit of possibility for error.
I'd be hesitant to mess with the front part of the mag catch since there is a little bit of play already. I'd prefer to just have the rear of the mag lock in a little tighter, if possible.

What's a TiG?

 

[model 649]

TiG, or GMAW as it is lately called, is a form of welding. Glad you're up and running.......
Josh

 

[Jeffy56]

AK Jams

A suggestion before any modifications are attempted:

The bolt & carrier assy may not be traveling far enough back enough to cleanly pick off a new round from the mag. You can manually cycle the bolt and see if the problem still occures.

There may be drag from the gas piston in the gas tube. The gas piston is easily bent or may have come loose, or the gas port may be clogged.

Check to make sure the bolt carrier & gas piston move freely, that the recoil spring isn't broken or binding. With an unloaded weapon, remove the top cover and the recoil spring & rod. Hold the bolt carrier in battery and tilt the rifle muzzle up. Ease the hold on the carrier, it should unlock and want to 'free fall' to the rear by it's weight alone.

Test fitting the carrier and gas piston with a one layer wrap of electrical tape around the piston head will tell you if it is hitting somewhere in the tube. Be sure to remove the tape after check.

The bold lugs could be 'sticking'. Too much oil can cause that.

Alternately, one of the bolt lugs is cracked and about to break. Inspect bolt carefully in bright light.

I swear these things are like old Volkswagons. These are some of the things I've come across over the last few years. Some of these may be obvious but hope this helps.

Jeffy56

 

[WeedWhacker]

Jeffy, thanks for the ideas; if I ever run across the issue while live-firing, I'll be sure to check those items.

At the moment, everything appears fine. I've actually had similar issues while manually cycling two different rifles from two different places, but zero problems of that type while actually firing them.

The only issues still present at the moment is that one flings the brass a good ten meters or so away, while the other one doesn't... but tends to catch the spent shells in the action. I'll stick a recoil buffer in the latter one, and/or try a different recoil spring.