Temperature stability of burn rates

[Bunnybuster]

Does anyone know of a good online chart of the temperature stability of various powders.

I have about a 70-degree temperature variance between summer range time, and the winter coyote season.

So, I want to pay close attention to the temperature stability of my loads.

[JD11]

I don't know about specifics, but a certain line of Hodgedon's are advertised as being very temperature insensitive. Two are Varget and Benchmark. It's mentioned on their site, maybe you could get technical info by Emailing them?

[futuretrades]

the hodgdon powders that jd11 has mentioned are called extreme powders. you can go to hodgdons web site and find out how many they have and which ones they are. also a good description of what they are talking about.

[BabaOriley]

I've stuck to Hodgdon "Extreme" powders almost exclusively so far. I loaded some BL-C2 just to see the speed it seems you can attain with it, but it didn't seem any more accurate with that load than Varget or H4895. I have a pound of Alliant Reloader 10x, but haven't tried it yet. 10x supposedly produces some of the highest velocities possible, but I hate the thought of finding a great load only to find out it varies widely in performance due to temperature. From what I've read BL-C2 is one of the worst for this, and 10x can be temperamental too apparently.

[Rick in Oregon]

Baba: Despite what has been said to the contrary, two of my 204's thrive on RL-10X with both the 32 & 39 SBK's.

I usually test loads in late winter and early spring, and do most of my rat shooting between late March and mid-June here in OR on the high desert and in N. KA. Temps at testing range from the high 20's, usually in the 30's & 40's. The temps down in N. KA can reach the upper 90's in mid-June when we have our annual Rat Rodeo, but even then in those temps, I have not had one bit of problem with excessive pressures out of RL-10X.

This is not to say it is NOT a problem, just never has been with me since I started using it in my 204's in 2005. Of course on the open prairie shooting PD's near or above 100 deg F., I suppose it fully COULD be a problem, I just have no experience in those temps for prolonged shooting sessions with 10X. It has become my go-to powder for two out of three of my 204's, giving the hightest velocity with the best accuracy, but No. 3 has not been shot yet, so can only comment on the performance of two rifles shooting 10X, one a 12 twist, the other an 11 twist custom barrel.

[MuleyTime]

Baba: Despite what has been said to the contrary, two of my 204's thrive on RL-10X with both the 32 & 39 SBK's.
It has become my go-to powder for two out of three of my 204's, giving the hightest velocity with the best accuracy, but No. 3 has not been shot yet, so can only comment on the performance of two rifles shooting 10X, one a 12 twist, the other an 11 twist custom barrel.

Rick- sorry for hi-jacking this thread, but what are your favorite loads with 10x. I have tried Benchmark, Varget, and W748 with Berger 35's and SBK 39's. Nothing super impressive, so I thought I would go ahead and try some 10x.

[Rick in Oregon]

Muley: Because both of my loads with both the 32's and the 39's are just a hair over the Sierra max with no adverse pressure indications, I'd rather not list them on the internet in case some newbie starts right off with them. I worked them up carefully in both rifles, know they're safe in those two rifles, but in good concience can't/won't list them here.

From the above though, I'm sure you can read between the lines and come purty dang close to my loads in your rifle. Just work up slowly when at book max, a tenth of a grain at a time. I should also mention that my seating depth for my Sako is quite long, way over max overall length for the 204, as I single load that rifle from the bench, and never use the magazine (BR followers installed in both rifles). That fact alone allows me to shoot over max loads, as the case capacity has thereby been increased by the long seating of the bullet. The other rifle has it's max load backed off a couple of tenths from the Sako load, but that rifle has a custom chamber, so it is not transferable to SAMMI chambers.

With the excellent field performance of the 204R, one really does not need to hotrod it; it's pretty darn effective 'as-is'.

I'm just trying to do the right thing, hope you understand.