Not really a different powder, Doug. The ammo today has pretty much everything different! The shot is harder, wads are better, even the hulls are better with a better gas seal...
I think you need to figure out what game you will be hunting, and what ammo you want to use in your drilling, and then go with chokes that have the best chance of working with that choise. OR, do what i did, and have choke tupes installed...
DM