Powder temperature sensitity

[beekeeper]

We do not have a powder section I thought I would ask here.
I am looking for a temperature sensitivity chart that makes some kind of sense.
Looked on the internet and found a lot of info but little I could understand.
Is there a chart or pamphlet Like " Powder Temperature Sensitivity for Dummy's".

We have been having some unusually high temperatures and loads that I used before are not working out at all at the distances I shoot.
This Morning at 8AM it was 75 degrees and at 10AM it was 100 degrees.
Difference in point of impact was as much as 6 inches.
Same load ,same rifle.
Good head shots on the 465 yard silhouette at 8AM and 6inches low at 10AM .
Have eliminated brass , primers ,and bullets( Cast) so am concentrating on the powder.
Using 28 grains of IMR 3031 and a 150 grain bore riding bullet was holding a coffee cup size group and at 10 AM not hitting the target at all or so low as to not be an effective shot.
So I am looking for temperature sensitivity data on all powders to see if I have any fit to use on long range targets.


beekeeper

[Ranch Dog]

We do not have a powder section I thought I would ask here.

That is a good thought!

I am looking for a temperature sensitivity chart that makes some kind of sense.

I've never seen anything that identified powders by this criteria. I do favor the Hodgdon Extreme Rifle Powders. The first five on this page are my favorites.

[Ranch Dog]

We do not have a powder section I thought I would ask here.

That is a good thought!

Looking at it, I think "The Ammo> Rifle Reloading" is a good place for this to land...

[Fyodor]

The hotter powder gets, the more offensive it will burn. That's why a lot of long range shooters bring their ammo in cooler boxes. Air viscosity changes, too, which also has an influence on longer shots.

But I don't know of any chart. My long range friends all made up their own shooter's handbook.

[akuser47]

Yep it sure does shoot some using same loads from winter then summer. Alot of variation. Best to know what your load will do in what temp. Humidity. Elevation. So you can have your rig dialed in for that long distance data log that you recorded the variations.

[Maximumbob54]

I'm sold on Varget for it not caring about temp swings. I live in FL and my cousin elk hunts in the mountains of NV. She asked me to try handloading some .300 Win Mag ammo for her and I went with Varget for the supposed lack of care about temperature changes. That bull went down at a little over five hundred yards. We both now swear by the stuff. Oh, and a Hornady SST 150gr put him down on his knees and he fell over dead as a door nail. I am now favoring that bullet for most anything within reason.

[akuser47]

I'm sold on Varget for it not caring about temp swings. I live in FL and my cousin elk hunts in the mountains of NV. She asked me to try handloading some .300 Win Mag ammo for her and I went with Varget for the supposed lack of care about temperature changes. That bull went down at a little over five hundred yards. We both now swear by the stuff. Oh, and a Hornady SST 150gr put him down on his knees and he fell over dead as a door nail. I am now favoring that bullet for most anything within reason.

You are correct varget is very consistent over a wide temperature range. A great asset in many cases.

[Steve]

The big bragging point they make about IMR 8208 XBR is how it performs over a wide temperature range. What I found with my 223 rifles made a believer out of me.

[beekeeper]

I understand the use of varget and 8208 in most temps is great except if you don't already have it you ain't gonna get any , at least in the area where I live anyway.

None of the LG's around here have seen Varget since 2008 and $33.50 a lb for 8208 is a little more than I want to pay.
It's not that I can't afford it, I just hate to get scalped and not get a kiss while they are doing it!

Did find out I can use surplus WC860 in a couple of my 8MM Mausers and have it perform very good.
The third one I might as well have been throwing rocks.

Have some SR-4759 I am going to try next range trip in a 7 MM.
Friend and I are going to do a fire and ice test with it to see just how temp sensitive it is.
Am hoping it will survive the test as I am still on the hunt for a good 7MM powder as it is my favorite caliber.


beekeeper

[akuser47]

I understand the use of varget and 8208 in most temps is great except if you don't already have it you ain't gonna get any , at least in the area where I live anyway.

None of the LG's around here have seen Varget since 2008 and $33.50 a lb for 8208 is a little more than I want to pay.
It's not that I can't afford it, I just hate to get scalped and not get a kiss while they are doing it!

Did find out I can use surplus WC860 in a couple of my 8MM Mausers and have it perform very good.
The third one I might as well have been throwing rocks.

Have some SR-4759 I am going to try next range trip in a 7 MM.
Friend and I are going to do a fire and ice test with it to see just how temp sensitive it is.
Am hoping it will survive the test as I am still on the hunt for a good 7MM powder as it is my favorite caliber.


beekeeper

That's true as well. Keep us posted to your results.