Some folks like to do that... but I would say no, do the test at 100 yards. Sometimes folks will shoot a test at longer range, and disregard the horizontal dispersion (you see the ladder tests often done like this)... but the problem with that is the horizontal dispersion may not be wind induced at all; sometimes the barrel is throwing the shots to the side.
The best advice I can give you would be to shoot your sighter/foulers and re-set your scope's turrets to get the bullets as close to the point of aim as possible. It's very difficult, and sometimes impossible--to read a target where the groups are forming well away from the aiming point. In these cases I don't usually offer an opinion.
Use a target with identical aiming points. Make yourself a target with graph paper and a permanent marker, drawing black or dark blue squares. Level the target. Make sure you adjust scope parallax, and make sure you're getting the proper eye position on the scope. Use a sand bag for a rear support on the stock... and a good front rest or bi-pod. If you're shooting off a bench, and using a bi-pod, I like to put the feet on some flat sandbags so you can front load the bi-pod a bit.
Shoot only when you're ready... when you've had enough sleep. I get targets from clients all the time with three paragraphs of disclaimers right off the bat... "I had a guy shooting a 50 BMG on the bench next to me... I had a head cold... I had an argument with my girlfriend/wife just before going to the range... the wind was blowing 30 mph and gusting to 40..." or whatever.
So you need to choose a good day to shoot. Try to make sure the light conditions are good, and the weather isn't too rough. Shoot a few practice shots to get warmed up before you shoot the test. Allow plenty of cooling time between shots... and take your time.
Good luck.
Dan