I've been shooting Winchester and Wolf in my RRA M4.  Every now and again, when I fire and weapon cycles, it is not extracting the spent case.  Upon further examination, the base of the case is missing metal due to the extractor.  I have to send the old cleaning rod down the barrel to push the case out.  Any suggestions??  Thanks

The case body looks fine.  Its the rim right behind the extractor groove, like its ripped.

I had about 400 rounds thru it.  I will clean it and try it again.

Does it happen only with the Wolf, or with both ammo types ? Also, is the barrel chrome-lined ?

In one of my rifles with a non-chrome-lined (chrome moly) barrel, this would happen every time with Wolf if I got the chamber hot using the following procedure: (1) fire off one 30-round mag of Wolf .223 ammo at a rate of about 1 shot per second, (2) insert a fresh mag and cycle the round into the chamber, (3) wait 1 minute, and then (4) fire. lmost without exception, this would result in a stuck case with the rim ripped off. Happened with both old (lacquer)and new (polymer) type Wolf ammo. The chamber was in spec with respect to headspace.

My chrome-lined rifles shoot Wolf just fine.

Its Chrome-Moly.  It was doing it to Winchesters also.  Kind of funny.  I took one of my sons friends with us to shoot today.  It would do it to him almost without fail.  I never got one today but the kid had 2 per mag.  Its probably a dirty chamber.  I will strip it down and take her out again, see if it helps.  Thanks guys