I am starting load development on my pet project Model 7 LSS Thumbhole 300 RSAUM. Powders tested will be H4350, H4831SC, IMR4350, and N-550,using 150, 168, and 190gr matchkings. Brass is std remington stuff all weighed and seperated by weight. Same OAL. Primers to be tested thus far on the list are CCI 250 Lg rifle Mag, and Federal Gold Match 210M. Anyone care to add any other primers to this lst, or known good powders for this caliber?