Tall Target Test
A measured vertical dialing test that confirms whether a scope's clicks deliver their stated value, catching small tracking errors over a long travel.
The tall target test uses a tall paper target with a plumb vertical line and precise reference marks at known distances up its length. The shooter fires at the bottom, then dials a large, known amount of elevation and fires again near the top, measuring the actual distance the impact climbed. Comparing that real movement against what the turret-tracking claimed reveals whether each click is truly worth its advertised value.
The point of dialing a long run is that small per-click errors are tiny up close but accumulate into something measurable over many units of travel. A scope marked in minute-of-angle or milliradian might prove to move slightly more or less than spec, and the test yields a correction factor you can apply to all future dialing. Keeping the target dead plumb is essential, since any lean throws off the measured rise.