How to shoot a group that counts: the test protocol

A group that gets compared with another — between two lots, between two barrels, before and after work — counts only if it was fired to a protocol that eliminates, as far as possible, everything you do not want to measure. The one used at the qualification test facilities translates to the demanding shooter’s range almost without change. The ammunition: one lot only for the whole test, chosen among those with small and consistent dispersion, because a dispersion test on the rifle requires that the variability of the ammunition be eliminated as far as it can be. The cartridges are conditioned at 21 ± 4 °C for at least two hours immediately before firing, standing upright, primer down, in blocks with separate holes, with the conditioning cabinet near the firing line so that a cartridge is never out of condition for more than a minute before the shot. The ambient temperature of the test is 21 ± 4 °C as well. If a mix of types is fired, the order of the shots is recorded, so that every coordinate can be attributed to its cartridge.