Re: how many rounds at the range do you fire
My load/ladder testing involves at least ten rounds of each increment fired on a single aimpoint. I will generally do initial tests for 4-5 increments, each increment on its own aimpoint, fired in a round robin sequence (i.e. a sequence of one round from each incrment to its own aimpoint, then another sequence, until all rounds are expended. Match conditions (time limits, firing cadence, shooting position, and so on) are followed as closely as possible. Increments are approximately 1% of overall charge weight.
Load refinement testing brackets the likeliest load by .1gr increments, typically 10 rounds of the selected increment and .1gr above and below, again fired in round robin sequence. Usually I will move out from 100yd to 200yd for this test firing sequence.
Greg