I’m not sure which is least temperature sensitive but I’ll research that and go with the one least sensitive.
From what I've read, the Australian Extreme powders are probably the most temp stable.
The newer generation of RL powders are said to be more temp stable than the older ones.
Have you tried RL-26? It reportedly is a high performer in the 300 WM with heavy bullets and has a good temp stability profile.
DF
Edited to add, H-1000 has been a favorite in that application and is temp stable. There are claims that RL-17 is hard on barrels, but I use it in my 6.5-284, as it's a top performer in that round. I don't shoot it that much...
