Yossarian: Excellent question. I shoot in competition with an AR at 100, 300, & 600yds with aperture sights. True I use a heavy bullet (77gr). I have used a variety of aperture sights. I am capable of 1" roups at 100yds. I think what's more important than the sights are the Trigger, Barrel and ammunition. This all pales in comparison to understand the physics of a projectile. There are many good aperture/open sights for bolt action guns.
The other question you might ask yourself is this for hunting or target shooting? The two have different configurations, barrels, actions, round counts, etc. Oh, and the previous poster that suggested Williams Sights, excellent sights! They offer open and aperture. http://www.williamsgunsight.com/