Todd,
No easy answer to that one, and no way to tell by what someone else's gun shoots best. Buy a 5-pack of several different brands and see which one or ones your gun likes best, that means some time shooting for groups with your gun. Benchresting slugs is kinda tough, either cheat with a sandbag/shot bag behind the butt, or shoot sitting or standing from a rest so you don't get pounded enough to develop a flinch. Be sure you can separate how the gun is shooting from how YOU are shooting no matter how you decide to do your testing.
Good luck with it, hope you find a load early along your gun shoots well.
lpl/nc
