Temp insensitive powders?

[black mamba]

What are the most temperature in-sensitive powders?

Maybe one or two medium and slow burners. Thanks.

[Poindexter]

In shouldered/ necked rifle brass I love Varget (20" .223, 22" .338 Federal). I have tested Varget in both calibers down to -30dF and still have angle of critter at 200meters without moving my scope from zero at +70dF.

This winter I have tested three pistol powders in .45Colt down to -42dF. Each of Universal Clays, HS-6 and TiteGroup did great, though lubing cast bullets below 0dF gets into some pretty runny stuff.

I think Universal Clays was starting to run out of snot at -40dF, but I only hunt down to -30dF (for very hort periods) anyway, so the -40dF datapoint was just a confirmation of the data I already had.

All four did fine with regular primers. I did fool a little bit with SRM primers in .223 with Varget, but it wasn't necessary. All did fine with leaving the reloaded ammunition in my truck bed for a few days before testing, running warm from the house ammunition in a cold firearm (I have a locking tool box in my truckbed), and all four did fine with both the firearm and ammunition cold soaked outdoors.

FWIW the only pistol powder I know of with temperature issues is H-110. I didn't believe all the reading on the internet until it happened to me too.

[Unclenick]

Hodgdon's whole line of Extreme powders are temperature compensated. Their Extreme Tour has examples. Pick one appropriate to your chambering, though, and be aware any such compensating scheme works best in a particular chamber under particular conditions. Varget, for example, is known to perform good temperature compensation in .308, but not to show so well in .223.

[black mamba]

Thanks, fellas. I do like HS6 and Varget, need to get some H4895 as well.

[Sevens]

This may be basic and obvious, but it seems relevant.

While Hodgdon does market their "extreme" line that is intended to address this issue directly, it's been a long known fact that most all loads will, if anything, run higher pressure in warm situations.

Or to put that another way... if you develop a load to run the very ragged edge of sanity and you do all your work in cool weather -- that load may go well over the red line and do NASTY things if you bring out on a 95 degree day.

On the flipside, if you develop a load that runs the ragged edge of sanity and you do all your development and testing on a 95 degree day, then you (theoretically, of course! ) should be safe to shoot that load (in that gun) all year long as long as your temperatures tend to be a little less extreme.

Of course, take that load to the desert and you could be asking for trouble.