People have won matches at 200 through 600 yards with several makes of 168-gr. bullets with any charge weight between 41 and 44 grains of IMR4064 or between 39 and 42 grains of IMR4895. All with the same barrel. There's not much difference in accuracy attainable with any charge weights in those ranges. If you shoot at least 20 shots per test group.
If one shoots 3, 5, 7 or 10 shots per test group, there's a 95% probability that all groups will be somewhere in the following percentage spread of what one group's extreme spread is:
3 shots, 41% to 244%
5 shots, 66% to 153%
7 shots, 74% to 134%
And you don't know if that single, few-shot group fired is at the large end of several or the small one. Ten or twenty shot groups are better:
10 shots, 81% to 116%
20 shots, 89% to 112%
I wouldn't get too concerned about muzzle velocity claims. It'll vary almost 100 fps for the average across several people shooting the same rifle and ammo. Same with different lots of powder and primer along with a weak firing pin spring. Hand held rifles shoot a given load much slower and with greater spread than fixed mount barreled actions. Your hand held rifle's ammo with a 50 fps spread and 20 fps standard deviation may well shoot in a 15 fps spread with a standard deviation of 6 from its barreled action in a fixed mount or the rifle fired in free recoil.
