I have the same gun, using the 140 gr Accubonds and 58.5 gr or IMR 4350 I average 1", with the 140 gr SST's and 58.5 gr of H4831sc group size is down to about 3/4". Haven't tried the 150's except for the WW factory load. I figured the 140 gr Accubond can be one load for everything. I do have some 130 gr SST's and BT's and some 140 gr Sierra's that I haven't had a chance to load for yet. So many rifles, so many cartridges I just can't get to them all.