Copied from my post on AR15.com last night:
I am having problems with the bolt in my DPMS LR-308 short stroking on occasion and catching the next round in the middle of the case. Details and pictures here.
I noticed that there was some carbon and soot on the barrel in front of my gas block (PRI low profile) so I took the hand guard and the gas block off to have a looksee. The carbon was about 1/8th inch from the forward edge of the gas block, and underneath there was a thin coating of carbon/soot everywhere the gas block covered. I cleaned off the surfaces and put it back on, taking care to torque the two set screws down to 30 inch lbs this time with a bit of loc-tight.
My question is: will that little bit of a leak cause the bolt to short stroke (about one in twenty rounds)?
Nobody has responded about the gas block question. I'm pretty sure that there's no possible way to stop all of the gas from leaking out. How much is too much?
When I first put the rifle together, I didn't have the fantastic Wheeler FAT Wrench, so I just kinda tightened the set screws a bit thinking that they seemed a little frail. This time I put the FAT Wrench on it and cranked them down to 30 inch pounds. I'll try to shoot it this weekend and see if that helps, but I won't start out shooting my handloads.
I bought some Remington 150 grain Cor-Lokt ammo last night that I'm going to send down range to see if they feed properly. I'm also going to chamber and eject them first to see if the bullet gets jammed down into the case neck like they have been doing with my handloads. This is also a problem with the Black Hills 185 grain hollow points that I shoot in my Kimber. I need reliable ammo for that gun too, but there is still a lack of .45 ACP on the shelves in my town.