Hodgdon added some new powder temperature sensitivity charts to their website. They also updated the burn rate chart to include some other newer powders. I found the powder temperature sensitivity data interesting (at the very bottom of the pages). The H4350 results in the 30-06 is very impressive and is not that surprising how well it did from my experiences. What surprises me most is the N560 on the 300 Win Mag data. It gained 121 fps over 125 degrees. That's almost 1 fps per degree. The 5 series powders (N5xx) are all double based, which I know have temp issues anyway. I figured R22 would be about on par with these. I'm a little surprised on the IMR 4831 powder results in the 300 WM.

Something many shooters don't understand (i.e. non-reloaders) is about the temp issues and chasing only velocity. I spoke with a guy the other day about some 28 Nosler ammo, and he wanted going literally as fast as possible. I explained that I could accomplish this in the summer time with a double based powder, but that the velocity would not be there in the winter time in the cold temps. But the velocities would be changing up in depending on the season and temperature. He thought I was fooling him. A lot of shooters want, what I call, Ricky Bobby load. They only want to go fast. But they don't understand how important it is to have a solid load that is consistent in all temps. When you have a powder that has a major change in velocity and pressure due to temps, the load WILL change. Meaning the accuracy, the pressure, the velocity- all that will change when shooting in various temps. But can certainly get more velocity with the double based powders (over your single based powders) when loaded to the max. But load to the max pressure in the winter time, and you will be blowing primers and locking up bolts in the summer.

https://www.hodgdon.com/wp-content/...-results-for-temperature-sensitivity.pdf

https://www.hodgdon.com/wp-content/uploads/2019/11/burn-rate-color.pdf

Thanks Chad, I was wondering about researching temp sensitivity, Got the link now.

Thanks Chad. Very informative.

That sensitivity chart looks like really old data... I say that because when did anyone see Reloder 12 on the shelves.

I thought the same thing, but didn't pay much attention to it. I did see a date on there of 7/13/12, so about 7+ years old.

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