If you have a 3 holer you should be ok. Just run the heavier bulk birdshot (ie 1 oz or 1 1/8, not the 7/8 oz) and stay away from winchester from wal-mart. The federal from wal-mart is fine though.
Take it to the range, shoot it and if it doesn't cycle birdshot on #2 setting then worry about it
thanks for the reply. i will be shooting it next week.