I too have a 3 1/2" BPS with a 28" barrel. I shoot Winchester Supreme 2 ounce and 2 1/4 ounce #4's. I shoot a Pittman ported turkey choke....constriction of .670. I know several people who shoot a BPS, and all get good patterns from the Winchesters. I'm getting ready to order some ammo from nitro and I may go ahead and order the rhino choke as well. Their web address is:www.nitrocompany.com