Thanks for the replies. A little history on gun. Bought new, CSS conversion kit, 4 gas ports unobstructed. I did shoot 15 cheap Winchester rounds before the conversion kit. It cycled all 15 flawlessly. I don't remember specifics on the shells, just some I had laying around from last years dove season. I'm sure I got them at Walmart. It won't cycle 3dram winchesters with factory plug, or auto plug now.. I'm gonna take your suggestions and do some reading.