I am going to second 4831sc and 142 smks. I am also shooting a 28" barrel so, theoretically, I may be getting a little more from the slower powder. LongRange has never steered be wrong so find out what you can get a few pounds of and start experimenting.

ps 4831sc is everywhere around here and I can load .260, 25-06, 300 wm and if everything works out, 7 SAUM with it. Results still pending on the .300 and the SAUM is a pipe dream.