Squib308 explained: agree sounds like an ammo problem. perhaps the brass is bulging? Have you ever inspected the winchester brass in advance of vs. just after firing? Where by do you see everything that excludes pump shotguns from the entirety of segment 121? If which were the situation, the "sawed-off https://highimpactrounds.com/product/mossberg-590a1-tactical-12-ga-20in-8rd/