It's could be another case of poor primary extraction. Close the bolt on an empty chamber and see how much space there is in between the front side of the bolt handle and the receiver. Use a feeler gauge to get an accurate number.
BangPop-
Moving the handle closer to the aft end of the receiver. is only one aspect of the five part equation to bolt/handle TIMING.
OP-
Burnish the tool marks from the chamber with a fired piece of brass w/ 400 grit lapping compound.
