I dont know why this is happening, but all of a sudden my Remington 870 Police ((wood stocks)) stopped extracting shells. Before Today,..it was working like a dream. Im not a gunsmith so I dont know why this is happening. I can speculate this:,... The extractor does not appear to be going fully into Battery,..or the extracter claw Hooking onto the rim of the case. As a result,..there is that tiny bit of headspacing causing the shells to bulge when this shotgun is fired. ??? It appears that when the shotgun is fired that during the recoil process, the rim of the shell casing is slamming into the extractor. This is why you see the mark/fingerprint of the extractor dented into the rim of the shell casing.?? But I may be wrong. Imnot a gunsmith.