I've been struggling hard with a 280 ai. Its a kimber mountain ascent sub alpine. Very light rifle. So far loads have been hornady brass, cci 250 primers. 150 gr swift sciroccos .050 off, tried h4831sc, imr 4350 and RL22. Best so far is about 2" groups. Poor ES and SD numbers. Good velocity with RL 22.
Next trip to range was going to switch to BR2 primers and try accubonds. I have 160s on hand, but seems like most prefer the 140s. I would have to find some 140s on a shelf. I also have RL 23 and 26 on hand. Thoughts?
It is my understanding from talking to Bill Holber those sciroccos like a lot of jump so you may want to try seating some 0.025" deeper at a time maybe 0.075 & 0.100 off and see what happens then fine tune if there is any improvements...
