Squib308 reported: agree looks like an ammo situation. perhaps the brass is bulging? Have you ever inspected the winchester brass prior to vs. just after firing? MGL Chapter a hundred and forty claimed: “Huge capability weapon”, any firearm, rifle or shotgun: (i) which is semiautomatic with a set significant capability https://highimpactrounds.com/product/mossberg-590a1-tactical-12-ga-20in-8rd/