I've been trying to troubleshoot this AK-74 over the past several months.  Rifle is Bulgarian kit custom build with non-original new barrel from KVAR on Nodak Spud NDS-2 receiver and is wearing an AK-105 gas block from KVAR.  The barrel is cut down to 14.5" and battlecomp 1.5 permanently pinned.  

Now for the issue.  It's weird--it functions fine for about 150-200 rds, then towards the end of the range session (usually) it starts to have one or two failures to eject. Typical ejection pattern is that spent casings are thrown high and directly to the right (so high that they often hit the overhang above with considerable force at the local range!) but then occasionally they just tumble out about 5-6 feet at about 2 o'clock.  So I'd say the ejection pattern is not completely normal--at least not consistent.  With my SGL-31 the ejection pattern is VERY consistent, so much so that you could probably find all the spent casings in a 3' circle about 20 feet away and at about 2 o'clock from the shooter's position.

Now last weekend I took the gun to the range and has this major jam.  The empty casing (Silver Bear ammo) was turned around backwards so that it was wedged between the bolt and the chamber.  Never seen anything like this on an AK before.  (In fact, my SGL-31 has never jammed once after about 1500 rds).  Here are some pics:






Another thing to note is that there is considerable wear on the TWS Dogleg rail.  The aluminum is getting chewed up along the top, which suggests that rounds are coming up high as they eject.  Is this normal?  I'm not so concerned about the cosmetic issue, but the function of my AK is of paramount importance.  If you guys have any idea what be causing this problem (bad extractor? ejector?) let me know.  Thanks.

Have you shot it with the stock dust cover on? That is the very first thing I would do.

i would too

Could be your extractor.

I will try this, but again it since it only happens every 200 rds or so, I may never see the issue (that is, unless I burn through a whole tin of 5.45).  One thing to note is that there doesn't appear to be any rubbing of the bolt carrier on the TWS dust cover--at any rate there are no wear marks on the rail other than the part getting chewed up by the ejecting rounds.  I might also add that I've used the same TWS dust cover with my SGL-31 with zero problems.

It looks to me like your empties are bouncing off the dust cover. I'm betting that every now and then, one bounces back into the receiver or can't get out.

I wonder if that could be the ejector tip on the rail causing that?

Try getting out your calipers and measuring the dimension from the top of the receiver to the bottom of the TWS cover. Then repeat with a regular dust cover. That might tell you if the TWS cover is blocking the casings in.

Just measured it.  It's about a 1/8" difference between the two covers (the stock Bulgy dust cover has that much more clearance).  Is this enough to make a difference?  I'd be curious to hear if other TWS owners have had similar issues.

I'd be willing to bet that's the problem. I don't know I'd there is a way to adjust the ejection, or if you need to remove material from the TWS top cover.

I am betting top cover, but I would also check the extractor because if it's not hanging on the round would not be thrown but could just tumble around when hit by the ejector.

You said it gets worse towards the end of the session... perhaps when the extractor is gummed up a little?

I concur. Even if the top cover isn't directly the culprit, it can't hurt to remove about 1/8" from the TWS top cover.  Problem is,I'm really not handy with this kind of stuff.  It would be nice if I could find someone to do this properly.  I do recall a thread where a guy removed material from the left side of the top cover to accomodate a left-hand charging handle and it turned out looking like factory--wish I could find the guy and pay him to do mine as well.

Regarding the extractor, is there something I can visually check to see if it's good to go, or should I just get the extractor replaced and see if that resolves it?

wow...that's some really soft metal on that dust cover.  holy hell.