Kota,
With regard to Brass, I don't have an answer,,,,I buy 358 brass.
Now about the load...I have found my best group (100 yds) using 4 shot groups, is between 1 1/4 and 1 1/2 inches. With Sierra Gamekings 225gr over IMR 3031 (42gr). My C.O.A.L. is 2.770
I hope this helps a bit, good luck.
