Have been using the 300 g Barnes expanders( w/knight EZ load Or sabot) in my Optima with good success and recently tried the Spit Fire TMZ's (Barnes yellow sabot) and was impressed with the tighter groups and flatter trajectory. Picked up some Knight Poloymer tipped ultimate slam bullets with the blue e-z load locally and although they load easily, the groups opened up a bit. Where can I get sabots for .451cal boat-tail bullets.