I have done a fair amount of 'testing' geared towards temp sensitivity in a cool to hot environment. I don't get much opportunity to shoot at sub-zero temps but I can shoot at temps over 100 degrees all summer long.
I would load and test in 40-60 degrees and then retest in 100+ temps. Some powders are pretty poor in this regard ie. H870, H450 and IMR 4064.
I found the Ramshot powders to fair very well in this environment. I have used them quite a bit and nearly always 'try' them to see if they work well. I use TAC more than anything else in that burning range. I use it in .222 through 30-30 and many things in between. I use Big game in 22-250 and 220 Swift. It is the only thing I like better than 4064 in 220 Swift!
I don't think Hunter is as good as the others and certainly not as good as Magnum as far as getting good velocities compared to similar burn rate powders.
