Re: Mossberg Bolt Action 20ga w/ full choke??
Super Full (turkey choke, Extra Full) is contraindicated for slugs, full choke should be fine.
Check the choke and make sure its doesn't have more than ,035 constriction and you are good to go, if you do your gunsmith can ream it out a little. Personally I get my best accuracy with IM choke. It help centers the slug before it leaves the barrel. Most barrels are a bit over size so cylinder bore can be a crap shoot, some will be good and others not so much.
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