02-17-2020, 01:44 PM
I suggest you load 1 round in the mag, chamber then fire the round. If it cycles and locks the bolt back try two rounds. Make sure the BCG is well lubed. If you experience cycling issues try factory ammo like Hornady 123 grain ELD-M, SST or 123 BTHP. If the rifle will not function with four or five rounds in the magazine sounds like there might be an issue. Inspect the brass and look at the brass and see if the extractor is leaving marks on the case rim. Is the rifle failing to eject or only failing to feed the top round in the mag?
I have the same basic upper but with the heavy profile CMV barrel. Mine functions with a supplied carbine buffer and spring. The symptoms of over gassed and under gassed can be the same. More information and pictures will help if you continue to have problems.
I have the same basic upper but with the heavy profile CMV barrel. Mine functions with a supplied carbine buffer and spring. The symptoms of over gassed and under gassed can be the same. More information and pictures will help if you continue to have problems.