First day here and I have a question... While on leave from Afghan I bought a RRA CAR4 and then built my Stag lower with DPMS LPK Magpul MBUS front and rear and cheap UTG railed handgaurd  ( no optics yet leaning torwards AP or EO).. I am new to owning an AR just not new to operating one.  I will add pics as soon as I figure out how to do so on the Gov equipment I am using here.

I only got a chance to fire about 100 rds down range (thats all the wife would allow) since I was suppose to be spending time with the fam...

I kept having the same issue after every round, the bolt would cycle to full battery and have a new round to chamber.  Problem was that the spent round was still in the chamber.  I am guessing or assuming ( I know bad woeds to use) that the extractor spring doesn't have enough tension to hold on to the spent brass and that is my problem.  I just bought the extractor upgrade kit from BCM and it is waiting for my return home to try that out.  If anyone has any more ideas of what it could be please feel free to add to my limited knowledge.

The BCM extractor upgrade is a great place to start but also take a look at your extractor to see if there are any visible burs or machining errors on it that would prevent it from grabbing the rim of the case.

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Or just stick a # 60 o-ring on it to see if that improves extraction. If it does, get the BCM kit.

Thanks everyone seems like I am on the right track then.