So I acquired a CZ550 that was built by GA Precision as a 500 Battleship, Apparently a Rigby cut off around the shoulder and necked for a .510 projectile. I am have that rechambered to 505 Gibbs and am looking at doing some odd ball experimenting. Does anyone know of anyone that has worked up or QL-ed 750Gr Amax in the cavernous gibbs? I have an actual .505 Barrel to thread and chamber as well that was will go on it later in life.