I am assuming we are dealing with bolt actions. I post a target, place the rifle in a rest and rear bag, remove the bolt and sight down the bore, moving the rifle until the target's bull is centered in the bore or close to it. I then, while trying my best not to move the rifle, adjust the scope until the reticle is centered on the target's bull. I often ask someone else, my wife usually, to do the scope adjusting while I keep the rifle steady.
Then I fire three shots (centerfire) or five shots (rimfire) and again center the reticle on the target's bull. Without moving the rifle, I adjust the scope until the reticle is centered on the three- or five-shot group. At that point, I have the scope looking where the rifle is shooting, at least close enough for some final adjustment.
The above target shows my initial five shots in the lower right center of the target. I then shot five into the center bull to zero the reticle. Then I shot 10-shot groups starting with the upper left bull, then the upper right and the lower left. At that point my 78-year-old eyes were tiring - you can see how the groups were deteriorating as I progressed - so I took a break before shooting the last group at lower right bull.
I'm sure others will post their methods as well.
Ed
