Which of these magnum powders are the lest temp sensitive?

[rockchalk06]

Reloader 26
Reloader 25
H1000
Retumbo
Ramshot Magnum
N570

Looking at reaching 2800 FPS in my 26" .300 PRC with the 225 Grain ELD-M. All of the above listed, have safe charges up to 2800 and beyond. Plenty of load data between my 3 apps to safely work up.

Which of the above is the least temp sensitive? Which meters the best? Never used any of these powders before.

Thanks in advance OSA

 

[diggler1833]

Not gospel, but a good ballpark chart:

Generally anything out of Hodgdon's extreme line is going to be pretty insensitive to temp changes.

 

[rockchalk06]

Thank you. H1000 looks pretty promising.

 

[diggler1833]

Thank you. H1000 looks pretty promising.

It's also unobtainable, and there's reason for that: It is an excellent powder.

So is Retumbo.

Neither of those meter for crap though.

Accurate Magpro is a sleeper. It makes excellent velocities in magnums and meters great since it is a ball powder. Downside: it is a bit temp sensitive, and ES/SD can be a bit extreme until you get that case almost completely full. 72.0gr in my brother's 7 mag had an SD up around 24...72.3, it was down to 12, and by 72.6 it was 6 FPS for the SD.

 

[rockchalk06]

It's also unobtainable, and there's reason for that: It is an excellent powder.

So is Retumbo.

Neither of those meter for crap though.

Accurate Magpro is a sleeper. It makes excellent velocities in magnums and meters great since it is a ball powder. Downside: it is a bit temp sensitive, and ES/SD can be a bit extreme until you get that case almost completely full. 72.0gr in my brother's 7 mag had an SD up around 24...72.3, it was down to 12, and by 72.6 it was 6 FPS for the SD.

Ya, I'm seeing how hard it is to find now. Being the capacity this will take, I may have to hand trickle each case and do a double throw with my measure.

 

[Jcann]

I’ve been shooting H1000 for 12 years and it’s been very stable and consistent. It’s a stick powder so there is binding from time to time in my powder dropper.

 

[dennishoddy]

Just a comment and not an observation on the above posts which are very substantial, but the new powders are showing to be less temp sensitive than the classic lines of old.
Some of the classics are and will be great powders going into the future, but the new ones deserve their place in reloading.

 

[Ready_fire_aim]

It’s not on your list, but IMR7977 is a good modern magnum powder you might have better luck finding

 

[rockchalk06]

It’s not on your list, but IMR7977 is a good modern magnum powder you might have better luck finding

Thank you

 

[leemozoid]

WW296 always worked for me when I was actively shooting .357 magnum.