I built this gun a few years ago in steps every now and then. Finally got it almost done well before the AWB in this commi state took effect last year. Anyway the bolt carrier slams forward to about 1/2" of  hitting the front trunion and locks/jambs. I can get it closed with a rubber mallet and 5-6 hard wacks on the cocking handle. Headspace was correct, used guages and live round just to make sure it would close and lockup but I did not have the bolt in the carrier at the time. Pulled it out the other day and began putting internals in her and put in the bolt and carrier. Then I found out it had this problem. Could not find the issue, took everything out, cut and took out center rivit, tore out the rails and tried it then, no go. painted the trunion, bolt and carrier black and jambed the bolt and carrier in her in 3 times or so to look for wear. Noticed a little paint gone on left bolt lug but other than that nothing more. This was a Romy matching kit with a green MT virigin barrel. It has no side cuts or handguard cut so I had gotten one from Curtis that had those cuts and I completed the barrel build. Also I thought to myself that that last 1/2" puts the end of the piston into the gas block so I checked in there and found no rubbing or scaping on the top,bottom or sides. The gas block is a little canted but not that much. I do know I did NOT put the front trunion in my 20 ton press for any reason LOL

Anybody have a clue of what might be causing this or what to try?


Thank you

Jack

I had this problem on a Romanian AK new in the box. I bought another bolt carrier and it worked fine. Never did find the root cause though, just something about that carrier. It did work in another rifle I had though.

There is a groove on the side of the bolt.  This is a clearance for the extractor.  The groove has a ramp on either end.  If the ramp is not blended witth the bolt body - that is, there is a lip between the ramp and the shaft, it will "stop" just prior to closing.

There are also bolt lug clearance issues that can affect closing but these are not 1/2" out.