Thanks guys!
Northcountry -- It is a rifled barrel. Should shoot the 45s well too although I haven't tried that yet.
Mesa -- I saw those MGM shotgun barrels. I've got a couple of their rifle barrels that are extremely accurate and I really liked the idea of the 28 gauge in a 20" or 22" length. I almost ordered one, but they are definitely very pricey so I held off a while and then saw the 410 barrel come up for sale. I'd still probably buy an MGM if I saw a good deal on a used one though.
