Just got a mossburg 535 and testing different kinds of ammo to find out what will work best for spring turkey. I'm leaning towards the new federal premium 3 1/2 inch mag-shok with flight control. The pellets are mixed with a tungsten-iron blend. better than lead and steel. I just need some help with choosing the best number of shot. Any suggestions? ALSO, my extended choke tude reads "lead only" so will the tungsten-iron blend be OKor not?