er, ah blackpowderfever, your math is a bit off. His multiplier would be 4X not 8X. So it would be 16 clicks per 1" impact change at 25 yards. Dead on at 25 yards, then check at 100 sounds good.

Another way to do it (DoubleHH): remove theplunger and breechplug,eyeball your viewthrough the bore and center a distant object with the rifle held securely. Then move the scope's crosshairs to intersect with that same object. (I've cut a couple of notches in a cardboard box to hold the rifle and a distant light used as the object works well at night) That will usually get at least your windagevery close.

Another would be to fire 2 or 3 shots at25 yards (I would suggest only one if you are sure of your load and ability), then mark the center of those shots (hopefully one nice hole), then again aim at the bull and have a third hand move the crosshairs to center on the marked hole while the rifle remains steady. That method should get you close enough to move your target on out to 100.