Kingston got it right, velocity has nothing to do with a ladder test.
Nothing shorter than 300 and 500 is better.
David Tubb says he does his ladder testing at 200 yards. That's the distance I prefer as well. Beyond that and you have more variables that inadvertently effect the testing.
There variables in anything your shooting no matter what distance. I know Record holder1000 BR
Shooters who shoot ladders at 1,000 yards.
Not taking anything away from David Tubb his accomplishments speak for themselves.