Thank you Bill for that answer. Now I'm going to call BPI and as them about loading the Fiocchi hulls that I got from them that happened to be neither high OR low brass and created the question that I raised. I want to build a slug along the lines of a Brenneke with a gas seal in back ,whatever the amount necessry of fibre wads to fill the gap up to a .54 cal cast lead bullet. I intend to experiment with the length /weight of the bullet as well as the wads to get at least a 3/4 oz. projectile that will roll-crimp in the 2 3/4" shells. Ken