So for my new AR build i decided to have some fun and make it a 7.62x39 and, ironically, it feeds flawlessly and rarely has a light primer strike (which i know are common problems), but about 1 out of every 10 rounds will eject and load a new cartridge fine, but the trigger won't reset (hammer forward).
Gun info:
Lower is standard spikes with psa lpk
Standard carbine buffer in spikes tube w/ spikes spring
ALG ACT fcg
Faxon 7.62x39 16" barrel with midlength gas system, low pro gas block (came with barrel), and spikes gas tube.
Rubber city armory standard bcg wit 7.62 bolt, Red X enhanced firing pin
Originally i had a heavy (spikes T2) buffer in it, i figured between the mid length gas system and heavier buffer maybe we were under cycling just enough to not always reset the trigger, so i swapped the buffer out for a standard carbine buffer. Its maybe a little better, but not much.
I've looked over everything close and nothing in the fire control group, bcg, or gas system appears to be wrong as far as i can tell (im no expert by any means).
I've been using cheapo Tula ammo mainly, but i also tried some brass (sorry, don't remember specs, it was some of my buddies loose surplus) and i didn't seem to make a difference.
I've been keeping her well cleaned and lubed. Probably about 200 rounds through her.
Anybody got any ideas?