Best range for load development?

[Philip J Theodhor]

i know I'm going to get diff opinions on this but still like the feedback. This is a discussion I've had with my local gs and my shooting buddies. What is the best distance to test loads? 100? 300? 500? 1000?
Most of my testing has been done at 100. Gs says 300, but seems to me environmental factors would become too much of an issue at that distance to get true results for load development. What's everyone else do?

I myself prefer to use the 100 yd .mark for initial load development . Once i am satisfied with performance at that range I will move out to 200,300,400 yards. If all goes as planned I will move out even farther. However 100 yards is my go to stating point for load development work ups.