05-26-2024, 12:31 AM
I've owned and shot AR15s for 30 years now, I have 4 uppers, .223, .450B and 6ARC, (the newest build and the subject of this post). I built this upper a few weeks ago and I'm 150 rounds into it. No feeding issues at all. Today I'm 18 rounds into a 30 round 1/4 mile match, (which I am winning handily), and I get three jambs in a row. Nothing that I have ever seen before in any chambering. Has anyone ever seen anything like this? The cartridge is jammed 1/2" out of battery and looks like it was wedged into the chamber at an angle? The first two I ws feeding from a Bobsled, figuring that was the issue, (it was a .223 bobsled, not specific to the 6ARC), I loaded 10 in a duramag and the second round did the same thing. I pulled the bolt between each jamb and did not see any obvious issue. The only change I made prior was to put in a new recoil spring the day before the match, and I shot 40 rounds with the new spring before these jambs. Look at the pics and help me out here if you've ever seen this before