don't worry about the critter named on the box get the shell with the heaviest pay load ! turkey shot in most cases has the most shot and cost reflects that . Lead has worked for a long time ! I use hevi-shot on waterfowl but haven't seen a need to spend 3 times the money to bag a turkey yet ! + in a full choke lead MAY pattern better .
i like #4 or #5 shot ( my choice you pick your own , but i have experienced better kills with those ) better on big birds !
pattern your gun like it will be shot ! if you clean it every time you hunt then pattern a clean bbl. if like me you clean at the end of a season or after some event that makes it necessary then pattern it that way