RE: .270 Which bullet?
Practice and find what it shoots best and stick with them. I think you can get better than 1" groups though. I shoot 1/2" at 100yds. with my Savage .270 using Sierra Gamekings BTSP 130gr., the 150gr. shot 1" groups. The Gameking lays them over on the spot, holds together well and is very devastating, not a meat ruiner but devastating nonetheless.