Temperature sensitive Powders

Paztec24

Active Member
Joined
Sep 4, 2023
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30
Location
michigan
How much does temp affect bullet trajectory with different powders. I have been trying to find recipes with H4831 or H4350 because they are "EXTREME" and not supposed to be effected by fluctuating temps. But I have a lot of IMR 4831 and IMR 4350 that has a bunch of recipes for my gun. I live in northern Michigan where I can shoot in the winter at 0 degrees (miserable if any colder) and travel out west where it can be 90 for Sept Pronghorn. I do a lot of shooting when it's winter because things slow down, but not as much in the summer when there are activities with the kids - so I may shoot last in March when it's 35 out but go hunting in Sept when it's much hotter. Thoughts or experiences???
 
Temperature Chart.jpg
^about this much. ΔV [in Ft/sec]/°F
I didn't compile this chart and don't know where it originated from, but my experience with Reloder, IMR, and Hodgdon powders leads me to believe it's somewhat accurate.

Also read https://www.handloadermagazine.com/rifle-powder-temperature-sensitivity
 
Search is your friend on this topic that has been flogged about as much as the 6.5 Creedmoor.
 
How much does temp affect bullet trajectory with different powders. I have been trying to find recipes with H4831 or H4350 because they are "EXTREME" and not supposed to be effected by fluctuating temps. But I have a lot of IMR 4831 and IMR 4350 that has a bunch of recipes for my gun. I live in northern Michigan where I can shoot in the winter at 0 degrees (miserable if any colder) and travel out west where it can be 90 for Sept Pronghorn. I do a lot of shooting when it's winter because things slow down, but not as much in the summer when there are activities with the kids - so I may shoot last in March when it's 35 out but go hunting in Sept when it's much hotter. Thoughts or experiences???

I live in an area where we experience some moderate temperature swings, well below O F in winter to triple digit highs in summer.

My powder isn't recognized as "temperature stable"…..so here's my method of working with it.

I only do my load development on days are above 90F, allowing a few hours for the rifle and ammunition to achieve ambient temperature! This should provide a "near worst case scenario" for high pressures in summer high temperatures!

Then pick a few different expected temperatures, monitoring group size and your velocities. Assuming that the groups don't go to heck with the temperature changes. This should give you an idea of how the scope should be adjusted, assuming it needs adjustment. Document these changes for future adjusts for temperature changes!

Unless you experience some pretty extreme temperature swings on a hunt…..I think that this will keep you in pretty good shape! memtb
 
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Here in Arizona we get HOT 🔥 was working up some barns copper loads for my 7-08 for pigs in California. I didn't have a chronograph at the time so I was just going old school . Found a load that grouped great . I was lucky enough to meet Lance to check on some stocks and scopes for a build that's still in progress and was able to shoot across his labradar . Figured I'd be around 2800 or so as a mid book powder charge but it was way faster 3035 for the average with the 140. I shot two hogs then . When I did finally get back to shooting it was alot cooler and I'd lost north of 100 fps. The powder wasn't stable so I've been working up new loads with staball6.5 . So far so good . The gun shoots fast at 3060 with the 26in brux .
 
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