Bolt issues

[ckparker]

OK, I consider myself to be aleast somewhat knowledgeable when bit comes to the AR platform, but I have a problem I can't quite figure out. I was testing some hand loads yesterday, and everything I shot was stovepiping--subs, supers hand loads and factory. I swapped bcg's with my 223 and everything was good to go. I inspected the bcg, didn't see anything so I tried it in the 223-stovepipe. Both bolts have thousands of rounds through them with no issues, both are lubed well. Both extractors and plungers feel and look the same. Anyone have any ideas where to go next? Thanks.

[talonxracer]

Loose, blocked or worn gas key?

Did you remove the bolt from the BCG to inspect?

[ckparker]

Gas key is is tight, bolt looked good, rings were not lined up incorrectly.

[FireF191]

Does it do it manually, or only when the bolt is cycling while firing?

[ckparker]

Does it do it manually, or only when the bolt is cycling while firing?

It only foes it when I'm actually firing. Works fine, no noticeable binding when cycling it manually.

[talonxracer]

Are you using the same lower for both a 556 and 300blk upper?

[ckparker]

Are you using the same lower for both a 556 and 300blk upper?

Excellent question. I forgot that part in my original question. I am using thaw same lower. Also, and probably an important part, I'm using a brand new CMC 3.5 lb trigger (which is SWEET). That's why I didn't bring another lower.

[tfbit]

Do both bolts have o-rings over the extractor springs?

[talonxracer]

Are you using the same lower for both a 556 and 300blk upper?

Excellent question. I forgot that part in my original question. I am using thaw same lower. Also, and probably an important part, I'm using a brand new CMC 3.5 lb trigger (which is SWEET). That's why I didn't bring another lower.

Could there be a clearance issue between that one bolt carrier and the new trigger group, seems that is the common points for the failures.

[ckparker]

Are you using the same lower for both a 556 and 300blk upper?

Excellent question. I forgot that part in my original question. I am using thaw same lower. Also, and probably an important part, I'm using a brand new CMC 3.5 lb trigger (which is SWEET). That's why I didn't bring another lower.

Could there be a clearance issue between that one bolt carrier and the new trigger group, seems that is the common points for the failures.

That's what I'm leaning towards as well. I've never taken two uppers and only one lower out before. Don't know what I was thinking, especially with a new trigger thrown into the mix. Guess I'll have to table this problem until I can get out and do some more testing. I just hope it's been only the one bolt, I'd hate for the trigger to affect my 450 BM as well. Thanks for the info.