Hello, I'm brand new to the 300 blackout cartridge. I've been lurking for a little bit while I acquired parts for my build. Well I finally got all the parts and took it to my gunsmith for assembly. I got the upper back today and I went to hand cycle a couple of the remington UMC FMJ rounds through it, just make sure the action function. at first none of the rounds would chamber at all. After adding some more CLP it started to chamber the rounds it still seems to not want to chamber rounds from time to time and it seems to be random.
here are the specs on the rifle:
Rainier 10.5" barrel w/m4 cuts
Rainier Gen I upper receiver with m4 cuts
YHM BCG w/ standard Charging handle
The upper sits on a command arms pistol lower.
Magazines used were magpul pmags.
here is a pic of the issue and some parts on the upper:
Failure to feed/go into battery
Picture of barrel extension into upper.
Picture of BCG
I haven't had the chance to take it to the range to do a full on function test, hopefully get out there this weekend. If the gun fails to function properly I'm going to be really disappointed. I was looking forward to doing a 300 blk build and so far it's let me down but I'm not willing to give up on it yet. Help me diagnose whats going on please.