I have had this happen before duck hunting. What I did to fix it was: I took the gun completely apart, then I put the entire breach assembly in my solvent tank. Extractor, firing mechanism, I mean everything. I let it set in the tank over night, then took a toothbrush to it. After that I blew it out with my air compressor. then re oiled, this is key, VERY SPARINGLY. Checked for burrs, and reassembled. I have had no problems since. Sometimes with new guns the cosmoline grease they use to pack the gun in gets into the hardest to reach places, and the best way I have found to get rid of it is the trusty solvent tank.