Recruit start at 50 yards, if you are holding a tight group, like 3 shots within small area, set your sights, then shoot at 100 yards and see the difference, readjust your sights to where you are a little high at 50 and a little low at 100. This is the way I do it and it works fine.
One note, if at 100 yards you are all over the place try a different brand and repeat the above steps, I have known people that shot one brand through their gun at 50 with great results and when they moved to 100 it was all over the place, they tried another brand and got good groups at 50 and 100.
One other thing, do not even waste your time shooting at 25 yards, the difference between 25 and 50 is miniscule.
The Tazman aka Martin Price
Founder and President of
Virginia Disabled Outdoorsmen Club