When the gas pressure hits the chamber inside the bolt carrier group that force should push forward against the bolt initially, because it's lighter,and unlock the the locking lugs , then the bolt carrier group as a whole will move to the rear and cycle the rifle.
Short story is no, it shouldn't twist the fired round out of the chamber. If you are seeing the scuff marks from the extractor, it's from feeding the round in the chamber.
This usually happens with reloaded rounds that have been sized to a very tight chamber spec.
Last edited by 75370; 01-22-2012 at 03:42 AM.