I am shooting a 338Lapua. Load is 90gr of h1000 with a velocity of 2770 and no pressure signs. Sometimes the brass comes out just fine after firing. Sometimes it is stuck where I really need to lift hard on the bolt and pull it back hard. When it gets like this the brass is stuck in the chamber and I must push it out with a cleaning rod. The extractor has torn its way through the brass. I measured the good and torn up brass and compared them to the dimensions in the Sierra load manual. They both check out the same and within specs of the manual. Any ideas of what may be causing this?