if it was me i would get a rifled barrel new ones go for about 160 bucks and get some good sabot slugs like remmington copper solids or similar i went thru the same issue back when we couldn't use a rifle in new york state all i had at the time was a browning a-5 smooth bore and had to use those rifled slugs which at the time sucked maybe better now but a rifled barrel and some good sabots are the ticket in my opinion. good luck !!