I am having a problem with my upper and fired cases getting stuck in the chamber.  The upper has about 1000 rounds through it prior to this starting.  I did not have any problems with the first thousand.  But now I can only get about 30-50 rounds through it before the cases will start sticking in the chamber.  It will do it will all brands of ammo (wolf, XM195, Q3131A and IMI)  It seems to only start to do it once the rifle has a few rounds through it.  The upper is a factory Bushmaster if that matters.

Any help would be appreciated.  I used to depend on this rifle all of the time but now it has me quite worried about how reliable it will be when I need it.

 

tag

im having the same problem with a non AR15 semiauto. ejector is gripping good, but the case is just sticking in there after 80-120 rds.

chamber is cleaned and excess oil is wiped with alochol before shooting

have to tap it out with a cleaning rod and hammer

could this be a headspace issue, not seating the round all the way in and letting gas and powder between the case and chamber, gumming it up??

Are there marks from the extractor ripping through the case rim?
If there are not, you may have a weak extractor spring or broken extractor.

Quoted: if you have to drive the rounds out of the chamber then the chamber is fault, undersized or scored. you can use a chamber mirror to check for any scoring, sometime the resutant marks will show up on the fired case. if there is distortion of the extractor groove then the extractor is working. clean your chamber with a CHAMBER BRUSH, clean the extractor groove, and re test.

Chamber was clean, it always gets cleaned with a chamber brush after everytime I goto the range.  I will go and get a can of gun scrubber and give it a good spraying, clean again with a chamber brush and see if it happens again.  There are noticable marks on the case rim showing where the extractor is grabbing it.  

Tweak- As a side note on this its kinda funny that I never had this problem when I was at the LCR shoots.  My chamber must have finally dried out from all the rain in the NW and shrunk a little bit.

Haven't changed anything.  I looked at the extractor and it looks good but I had a spare so I swapped those out yesterday.  Hope to get to the range this weekend and see what happens.