My last .22-250 used the same load of Varget you list with both 50 grain TNTs and SXes.
I wore out my first .22-250 barrel with 40 grains of H380 under 50 grain SXes.
I have not used any of the 3 powders you list in .22-250. 4064 seems like the "rightest" in burn rate. The other two I have only used in .223. Check Hodgdon's data site if you have not yet.
Tom
Anyone who thinks there's two sides to everything hasn't met a M�bius strip.
"Camping places fix themselves in your mind as if you had spent long periods of your life in them. You will remember a curve of your wagon track in the grass of the plain like the features of a friend." Isak Dinesen
I burnt out a barrel using Benchmark and 55gr V-maxes. Very constant, accurate, and great temp stability as well. I also have used H380, which was very accurate and fast with the 52 gr Bergers, but did show instability on the dog towns in the heat.