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.