Powder Temp Sensitivity

HuntnID

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North Idaho
So this whole H1000 drought has really gotten under my skin as it leaves me with very little to shoot without running out. I shoot H1000 in my 2 338 Lapuas, a 338 Edge, a 7rm and a 300wm.

Ive behn kicking around load development with a different powder like IMR7828SSC which my 7saum absolutely loves. My question is:

Is there a resource that can ballpark the velocity changes one will see when going from summer(90* temps) to hunting season(20* temps) or does it change completely with each rifle?

Is there a generic input that people use for the powder sensitivity input field in Applied Ballistics?
 
the Hornady app has some fps/deg for various powders 1.06 fps/deg is the number it has for 7828. h1000 uses .46
 
H1000 is starting to pop up a few places.
IMR8133 (which is ridiculously hard to find too) is a good alternative.
RL23 is great, maybe able to find it?
RL26 is starting to pop up occasionally.
RL33 is dirty, but gives great performance.
N565 & 570 are non-existant, but work great too.
 
Depending on how temp sensitive the powder is I have one accuracy load that during the winter (Hunting load) it averages 3010 @ 40 o and is extremely accurate. When temps get close to 100 o
the velocity jumps to 3155 and is very hard on brass.

Normally most powders only react to high temps and if not used above 80 o the velocity will not normally change more than 20 or 30 ft/sec in the temp sensitive powders.

With the large selection of powders today, you shouldn't have a problem finding one.

J E CUSTOM
 
Thanks for the help. My main inquiry is mostly if there was a reference for how temp sensitive each powder is so when I find a load this spring, and shoot it this summer, I have ab educated idea how the velocities will change going into winter.
 
None that I know off.

In the past and present I've used mostly IMR powders. On my 7mm-08 and my 7mm Rwm mag I use 4064, 4350, 4895, and I'm doing some load development on my 7mm-Rem Mag with 7828. I have a couple of good loads with RL19 as well. All of them are temp sensitive especially RL19, the ones with RL19 are not at max so no pressure issues in the summertime.

In the summer or warmer temps I have a higher point of impact that is about 1.0" at 200m and average of 6" at 500m. I check my zero every time I'm at the range just in case and I notice the difference when the temps change.

My advise would be to use a chrono in both situations and see what you get. Each rifle is different so only way to know is to try it and see what you get.

Hope this helps
 
Thanks for the help. My main inquiry is mostly if there was a reference for how temp sensitive each powder is so when I find a load this spring, and shoot it this summer, I have ab educated idea how the velocities will change going into winter.

Also, your point of impact can change from morning to afternoon. Example if I shoot a silhouette match next month and we start the match at 9 am when it's about say 75 degrees, at 2 pm when it's maybe 100+ already there will be a change in speed and point of impact with some powders and in some more than others. The example I gave you before where I can get a difference of 6" is in the same day with IMR-4350 on muly co petition 7mm-08, these changes are not just from one season to another.
 
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