IMO with any load development a chrono is key.
Not only will a ladder or even the OCW show grouping tendencies but the chrono results normally will match. OCW says do not worry about a chrono and that is ok for most factory hunting guns.
For example you will see jumps of say 25 fps on each new shot then suddenly 3-4 shots will have a variance of only 8-10 fps and then start jumping 25 fps again. Those MV groupings normally match a target impact grouping. Those 3-4 shots indicate you may have a tuning node there IF the impacts match.
It is critical to plot each shot and MV. The colored sharpies work extremely well and will not effect grouping and will show impacts. I always use a plot sheet at the bench with a spotting scope and mark on the plot sheet each impact by number with a column for each number and MV. I time my shots so no closer than 1 minute apart.
Like some others pointed out you really need 300 yards and I like 400 even better, or so to clearly show the movement of the shots and groupings.
With any method you want to be able to have a load in the middle of a node, not the top or bottom and the grouping AND chrono results will clearly show you that.
