Hey I found out what it was, it was crud lining where the round seats in the bolt. My stiff brush wasn't cleaning it out, and I had to run the side of a screwdriver in there and out popped a lining of stuff. Seems like the round can mate better with the ejector and do it's job properly. Works like a charm now
I had that same problem before as well. Buy yourself a pick set from Ctire, nothing fancy. You'll be able to use them to reach in and scrap that crap out without having to disassemble your rifle all the way down.