Where people usually get into trouble is when they work up a great load at 60º at a near maximum powder charge and then shoots the same load in 100º and then starts expanding primer pockets or worse. As temperatures increase, pressures and velocity will increase, which can affect safety and accuracy. With these types of powders, some reloaders have a Summer and Winter load. I experienced this with IMR 3031powder. My 308 Win. 43.0 grain load of IMR 3031 with 155 bullets was fine at 60º, but at 95º, I loosened all of my primer pockets and had to toss the brass. No real loss because it was free Federal GMM brass, but it taught a lesson.
Nothing wrong with powders that are temperature sensitive, it just depends what your use for them is and understand what happens at either ends of temperature extremes. For my precision rifles, when I burn up all of my IMR series 3031, 4895,4064, 4320, 4350, 4831, I have started buying and using the less temperature sensitive Benchmark, H4895, Varget, IMR 8208XBR, H-4350, H-4831 and Alliant's new AR COMP.
These powders are more forgiving than other powders and they don't cost any more then their temperature sensitive counterparts. It just makes sense to me to use the less sensitive alternatives.
For the powders you listed, IMR 8208 XBR is the least temperature sensitive. 8208 XBR is actually an ADI (Australian Defense Industries) powder, not an IMR powder made in Canada as most of the other IMR rifle powders are.
Just build a load that isn't going to give you pressure issues when you start using them in high temperatures. I've shot up a lot of the powders you listed. Just be aware of this.
