My turkey gun is a scoped 20 gauge shotgun and I only use 2 3/4" #4's. Dead is dead as long as you have the right choke and shoot at reasonable ranges it is enough gun. Field artillery not necessary unless your turkeys are extraordinarily tough and you like getting thumped.
Good intentions will always be pleaded for any assumption of power. The Constitution was made to guard the people against the dangers of good intentions. There are men in all ages who mean to govern will, but they mean to govern. They promise to be good masters, but they mean to be masters.