I picked up a used Model 70 SS with BOSS in .300 Weatherby. It looks to be in great shape. it's VERY difficult to get spent (factory) shells out of the chamber. Unfired shells load and unload easily. I was using factory Weatherby 180 grain cartridges that fed in and out of the chamber without difficulty. Once fired we had to pound on the bolt handle to get the spent shell casing out. What do I do now?