I just ordered a Savage model 12 benchrest rifle in 6mm BR Norma. It has a 1 in 8 twist. I don't handload yet and am getting ready to order some Lapua factory loads. I see they come in 90gr and 105gr loads. Which would be best for beginning longrange competition. The range I will be shooting at has a max of 650 yards. Also what power range scope should I look at for this distance.