Squib308 claimed: concur feels like an ammo concern. perhaps the brass is bulging? have you inspected the winchester brass right before vs. just after firing? Choke: choke is a different discussion than shotgun shells, but what choke you happen to be making use of should really sync with what ever https://highimpactrounds.com/product/mossberg-590a1-tactical-12-ga-20in-8rd/