12-07-2012, 01:24 PM
New Upper. New BCG. Using two (2) lowers, each of which is known to work (4000 rounds thru one, about 1200 thru the other). Same problem.
Problem - with or without a mag in place, when you dry fire the weapon, the bolt will not unlock from the extension. If you don't pull the trigger, the bolt operates as normal. Once you pull the trigger, the bolt will not unlock, and you have to "butt bounce" the weapon to get the bolt to unlock. Same problem with either lower. BC is properly lubed. Wet.
One lower has a stock trigger from like DPMS (reworked by Bill Springfield, and has operated flawlessly for some 3000 rounds). The other lower has an AR Gold trigger (operated flawlessly for 500 plus rounds).
Does the same thing with or without a round in the chamber. So, its not ammo related.
Upper is unfired, and I discovered this while building some dummy rounds to make sure that I was properly bumping the shoulder back enough before reloading a whole bunch of rounds. Upper is a new Black Hole W in 6x45. Has that silver finished coating on the bolt, BC, and cam pin. Looks like silver parkerizing, but I just forget the name.
Its seems like the hammer is hanging up on the BC. I just can't figure out what is hanging up, and because the upper is new, there are no wear marks to suggest what might be rubbing.
Thanks in advance.
Problem - with or without a mag in place, when you dry fire the weapon, the bolt will not unlock from the extension. If you don't pull the trigger, the bolt operates as normal. Once you pull the trigger, the bolt will not unlock, and you have to "butt bounce" the weapon to get the bolt to unlock. Same problem with either lower. BC is properly lubed. Wet.
One lower has a stock trigger from like DPMS (reworked by Bill Springfield, and has operated flawlessly for some 3000 rounds). The other lower has an AR Gold trigger (operated flawlessly for 500 plus rounds).
Does the same thing with or without a round in the chamber. So, its not ammo related.
Upper is unfired, and I discovered this while building some dummy rounds to make sure that I was properly bumping the shoulder back enough before reloading a whole bunch of rounds. Upper is a new Black Hole W in 6x45. Has that silver finished coating on the bolt, BC, and cam pin. Looks like silver parkerizing, but I just forget the name.
Its seems like the hammer is hanging up on the BC. I just can't figure out what is hanging up, and because the upper is new, there are no wear marks to suggest what might be rubbing.
Thanks in advance.