Re: Ladder test 1 shot each load or 3?
I use up to six rounds per charge weight.
I fire at separate aimpoints for each charge weight.
I fire in 'Round Robin' order.
The trouble with using a single aimpoint for ladder testing is that bullet deviation seldom follows a logical or predictable path, in addition to which, sorting out all those impacts in a close vicinity can get pretty confusing.
As long as one keeps the sight adjustment the same for all shots, the different aimpoints can help sort out the specific effects of charge weight variations on POI variations and dispersions.
I do my load development shooting in two stages.
The first uses charge variations of 1/2% of the whole charge, extended from min to max published charge weights. For a 25gr average charge, I'll do variations of .3gr, and for a 45gr average charge, I'll vary by .5gr.
The second narrows in on specific charge weights which show a better consistency of impact points, and I'll vary them by .1gr, going from just above the next lower increment to just below the next larger increment.
Generally, this will allow me to narrow in on a better charge weight in just two sessions, while shooting up to six rounds per charge weight makes the statistical probability of success much greater. By using larger increments in the first stage, a lot of redundancy is eliminated, allowing more shots to be used at the various increments, allowing better statistical chances of success.
In the very rare instances where first stage testing shows no clear preferences, I will repeat the first stage with smaller increments, and if that doesn't work, I'll try a different powder.
Greg
