I am having the short stroke issue like most.
I HAVE researched the problem and am not just posting without reading. Just looking for some verification.
-16" barrel from SA
-Carbine Length
-15.0 gr Lil' Gun
-147gr bullets
-gas block full open allowing full flow (properly aligned)
I think this is being caused by shotty chamber finishing. All spent cases look like I put 100 grit sand paper to them. I am pretty sure that it is a barrel problem. Just want some verification from the veterans. About to drop some dough on a serious barrel, but want to make sure that I am going in the right direction.
"Only two things are infinite, the universe and human stupidity, and I'm not sure about the former." -Albert Einstein
It looks like the chamber is rough. To be sure try putting a factory round in the chamber it should pop out with little to no force or fall out on its own. I had a barrel with a rough chamber that scratched the brass up and would not eject.
I have a new CMMG 8" barrel doing the same thing. I haven't had time to figure out the fix yet. The round will fall out when the bolt is operated. I have switched to a M16 bolt hoping the extra weight will slow the bolt down just enough to eject the round. I haven't had time to test it out yet. I'll post the results when I do.
I have an M16 bolt also. It seems to short cycle but not enough to eject the round. half of them jammed the bolt open.
I tried changing between a carbine buffer and a H2 buffer and saw no difference either.
"Only two things are infinite, the universe and human stupidity, and I'm not sure about the former." -Albert Einstein
Umm...dunno how to better describe the issue. example of what else to include? I have pictures, load data, buffer type, bcg type, gas block settings, etc. If there is something else I can add, please tell me and I will do my best to describe it. No such thing as factory ammo anywhere in MS for 300 blackout. Loads are from pet load lists located here. Will check for drag and swap bcg's.
"Only two things are infinite, the universe and human stupidity, and I'm not sure about the former." -Albert Einstein
bamabaxter wrote:Umm...dunno how to better describe the issue. example of what else to include? I have pictures, load data, buffer type, bcg type, gas block settings, etc. If there is something else I can add, please tell me and I will do my best to describe it. No such thing as factory ammo anywhere in MS for 300 blackout. Loads are from pet load lists located here. Will check for drag and swap bcg's.
Well...i wouldn't consider what you include to be "Load Data". You omitted a couple of key pieces of info like what type/manufacturer of the 147gr bullet, what is your case trim length, and what is your OAL?
bamabaxter wrote:1.357" Case Trim Length
2.200" OAL
147gr FMJ M-80 pulls
cci 400 primers
Hornady dies
Lee factory crimp die
Ok, not sure if that bullet profile exists in Quick Load, but with 15 grs Lil Gun behind a .308, 150gr, Sierra HPBT MatchK 2190 seated to an OAL of 2.2 (.267) seating depth, indicates a very low pressure (31440)...i suspect the round you are using isn't developing enough pressure to fully cycle. 17 grs would get the round i listed into a desirable pressure range (~44000).
I think you need to work up a load ladder in .5 gr increments until you get a round that cycles (checking for pressure signs along the way of course).
