I find single charges in a ladder can lead to false results. I generally load 3 of each in a ladder and use a chrono since even good groups at shorter distances don't mean much to me with horrible numbers. That works fine at 600yds and in but I don't like to push much further than that with big spreads in MV.

Here is a load ladder shot with 3-shots each of 41.5gn, 42gn, 42.5gn, and 43gn of H4350 and 140gn ELD from a 6.5 Creed at 300yds. 42gn showed almost no vertical while higher charges did even though they landed in nearly the same spot. I then shot 3 groups of 5 at .010", .020", and .030" from the lands. 27-shots from start to finish and I have a load that is on it (.6MoA including the round that wandered right, ES of 11fps, and SD of 5fps) without chasing false leads from a single shot ladder.
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