Was just reading this and was wondering if this could be part of the problem I saw this weekend. Was with a guy shooting a Bushmaster Predator using some reloads that I had loaded for him. The rifle would not reset the trigger it appeared that the bolt was not cycling far enough to get the hammer to catch on the disconnect. The bolt would pick up another round but the trigger would not be reset. Could cycle the bolt by hand and the trigger would reset. Even had it to double fire a few times...the load that I had loaded was 22gr/H335 68Gr/HPBT CCI400. Could it be that the bolt was not cycling far enough back to make the trigger operate properly?
I'd guess trigger issue as well. I actually had this same problem this weekend with an AR I recently built. Well, I actually had a few issues because I was trying some different things. First the AR would not cycle on it's own, too heavy of a buffer spring, but I suspected that this might be an issue before I even shot it. Changed out the buffer spring with a friends 6.8 and it fixed the problem, and his 6.8 works great now too (no twang and almost no recoil now). Then once I got my rifle to cycle, the trigger would not reset. For some stupid reason I never preformed a functions check on it prior to shooting, or if I did (which I cant recall doing) it worked then. Anyway the trigger would reset if I pushed it forward after cycling, so that lead me to believe there was something wrong with the disconnect. On a visual inspection with the upper off you could see it get hung up. I lightly brushed the surface with a fine flat needle file, then some 1000 grit paper, then some polishing compound; no more hang up, and the trigger (RRA 2 stage) is slightly lighter on the first stage now too. Functions check is a go now, so now I just have to get back to a range and put it through it's paces.
