Re: stuck cases
I had the same issue several year ago. Not sure what was wrong because i replaced almost everything. If the barrel is chrome molly and not chrome lined the case may be getting stuck. Try some different ammo to include Wolf because its a hot load and steal cased. if you get it to cycle, the ream the hell out of the bore with a bore bush. i ended up putting the cleaning rod in a cordless drill, coated the brush in clp and ran it in the bore for a minute or two. Also look at the internals, may be an issue with cut down m-16 parts rather than real Ar-15 parts. Keep in mind the Ar is not a precision gun its an assault rifle or at least thats what it was designed for. If it were me, i contact the builder, its his problem to fix. If its gas, look at the carrier key, gas tube, gas rings, and front gas block for leaks. Also if you get double feeds, one round trying to get under the one not ejecting, most likely gas but also look at getting a D defender ring for the extractor.