There’s a lot to be said about what distance testing should done.
I test initially at 100 yds on a calm day (if it doesn’t shoot at 100, it won’t further out), I’m looking for bug hole groups. If it’s calm, I do the same at 200. I need to know that the gun and load shoots, sans wind, as much as I can. I want a NO wind zero.
So, now I have a load that shoots, queue the wind, shooting out to at least 200 yards, 300 is better. Setup a spotting scope, focus on the target then back off a bit until you can see the mirage, watch which way it moves. Check the wind speed, either through environmentals or with a meter. Make a correlation between the mirage, enviromentals and the actual wind speed. With your known accurate load, hold and shoot dead center. Where did you hit? Three o’clock in the nine ring? Don’t reach for the dial, hold off half the distance on the other side of the bull. Same conditions, same mirage, shoot, where did it go…10 ring right side. Hold further left in the same condition, shoot, bingo center X.
Now you’ve got that one condition figured out, apply what you know to different directions and velocities. Every time you shoot you add info to your wind database in your head.
It takes a while, but when you’re in a match and you can hit Center X holding off near the eight ring or more, confidently, you have arrived.