Temperature Sensitivity Testing

[Guy Miner]

Travis put in some work testing two powders, Ramshot TAC and Hodgdon Varget for temp sensitivity from -65 F to 140 F.

Good video & article:

EXTREME Powder Temperature Testing: Varget -vs- TAC – Ultimate Reloader

ultimatereloader.com

Guy

 

[DrMike]

Most interesting. Their results did verify what I've observed. My practise is to verify my load near the temperature I intend to hunt. I've never had a problem with accuracy and/or velocity when I hunted. It is always good to gain assurance from controlled experiments.

 

[RL338]

I think it is interesting that at 70* they both start an increase in velocity more rapidly.

 

[jimbires]

Guy , that's a good article , thanks for posting . I've done some cold weather testing in the actual conditions . I was surprised at what I found .

 

[Guy Miner]

I think it is interesting that at 70* they both start an increase in velocity more rapidly.

Of course, we only tested at three temps. I'm thinking that more data points would reveal the curve more accurately. We want to do more of this, but it takes a fair bit of prep to make it happen.

Guy

 

[TackDriver284]

That is a great article, enjoyed reading it. I like to verify my final charges during load developments by reading the charges / 3 round groups on paper where it shows a flat horizontal plane within a group of powder weights due to some temp swings on certain temperature sensitive powders.
I like to stick with temp stable powders.

 

[RL338]

Most of my shooting is done between 20*- 80*. Sometimes temps during the hunting season do go lower , but mostly 20’s to low 30’s. Very seldom I shoot above 80* , too long to cool barrels down. I do must load work up spring and fall (50*-60*) for hunting loads. That puts me + or - 30* for most of my shooting conditions. The only powder I can remember giving me grief was US869. I developed a load is summer (hot outside) and for the hunting season I lost 100 fps and a noticeable POI shift.

 

[jimbires]

I think it is interesting that at 70* they both start an increase in velocity more rapidly.

from what I've seen doing my testing , 90* will be the temp things take a big change . I'd like to see the data when more temp points are mapped out on the chart .

 

[wvbuckbuster]

Thanks for your time and effort. Very informative. Dan.

 

[TackDriver284]

I forgot to add, I need to keep an eye on my 300 Win Mag velocities because on the recent charges I made to test a 3 round group with RL-22 recorded 3115 fps at 65 degrees last week. I had remembered the velocity was 3165 fps around there when I shot it 2 years ago, and it was hot that time.

 

[xphunter]

Good info