A sporter weight 1;9?
Max accuracy will depend a bit on range. The 53gr HP Flat Base bullets will likely group the absolute tightest at 100 or 200. The 68/69gr HPBTs will likely group the absolute tightest at 400 through 600.
So if you don't have access to longer ranges, stick with the 52/53gr hollow tip flat base match bullets.
Machine guns are awesome until you have to carry one.