Home Forums Hunting & Shooting Ask The Gunwriters Mule Deer & others-Least temperature sensitive slow burning powders?

I am trying to settle on 2-3 powders at most that will work well across the range of bullet weights for the 270WSM, 280AI, 7RM and 300 WM. If they work for other rounds well that's a bonus.

The powders I am looking at are in the range of: R25, RS Magnum, 7828SSC, VV165, VV560, Mag Pro, Retumbo, H1000. Any others I should consider?

How do they compare for temperature sensitivity and lot uniformity? Do any of these have a broader loading application than the others? Do we get too Loony about temp. sensitivity?

Depends on your hunting conditions. I hunt deer a lot (and elk now and then) in pretty cold temperatures, so prefer the most temp-insensitive powders for those uses. For pronghorn hunting I don't really care much, as temperatures are going to usually be within 50-80 degrees, not enough to make much difference.

Even temp-insensitive powders will react somewhat to temperatures much above 80, just less so than standard powders.

Alsom temp-insensitivity depends quite a bit on the cartridge and use. Maximum loads with heavy bullets in smaller-bore magnums will probably show more temperature sensitivity than when the same powder is loaded in, say, a .30-06 with 165's.

In my own tests the Hodgdon Extremes have always done the best, but some others are pretty good these days as well, including RL-17 and Ramshot Hunter and Magnum. The big problem isn't the 100 or even 150 fps, but change sin accuracy and point of impact.

This months Barnes Bullets newsletter has a very nice article/test on that very subject.

http://www.barnesbullets.com/resources/newsletters/july-2010-barnes-bullet-n/

nsaqam,
Thanks for the link. Good article and interesting information.
Test

Unfortunately, they used the too-standard test method of just freezing or heating the ammo, not the entire rifle.

I have gotten very different results when testing that way, and when testing when rifle, ammo and ambient temperature are cold or hot.

There are several surprises there................based on JB's comments, it may be somewhat suspect.

MM

I thought so too.

In other words, you need to be willing to go out there and freeze your ass off?

I prefer to think of it as testing hunting rifles and ammunition under actual field conditions.

Freezing my ass off is, well, often part of hunting!

Come on John... any valid accuracy testing of shooting ammo cold temps should factor in the SHIVERING of the shooter, right???

If I were going to do such an article, I would want to run tests on loads after significant actions -- carry the rifles and ammo on horses for four hours on sub-zero days, then pull them out and test some loads. Or drive them around in a truck cab for four hours, get out, sling the rifle, hike four miles with it at low temperatures, unsling it and fire test rounds.

Wouldn't be too hard to some up with some tests and run them. I have a suspicion some of the outcomes might be somewhat different than tests at the shooting range, no matter the temperatures.

Dennis

Well, yeah!

Oddly enough, however, shooting at around zero isn't that bad. I pick a days when the wind isn't blowing, and since I grew up in Montana I know how to dress for cold weather. I also have my pickup truck (with a warmed-up engine) within 20 feet of the bench at either of the ranges I use--but don't remember ever having to get back inside, partly because I'm usually hiking back and forth to the target every few minutes.

John,

Have you had the chance to test Hybrid 100V for temp sensitivety?

Got a pound sitting around I haven't loaded yet. Here in TX temps propably doen't matter much, except the extreme heat.

Just curious.

Thanks,

Bill

proving once again than nsaqam is the "internet theorist nincompoop" that he is so often accused of.

I shoot year round up here, 90 above to -30 below on occasion. Velocity changes for a variety of powders, regular types and "temp insensitive" types and have not noticed much difference between them. I seem to get more velocity swing when the temperature goes from normal 65-70 degree days to really hot 90+ days. Havent noticed all that much velocity loss from normal summer temp to the dead of winter, maybe 50-75 fps. Not enough to concern me. My biggest challenge when it's 30 below is keeping chrono batteries warm.

Here a study that has some info.

http://www.shootingsoftware.com/ftp/Pressure%20Factors.pdf

tx270,

I've only testing H100V in cold weather, in one cartridge/bullet combo. It's definitely not one of the Extreme powders. Velocity was down a lot and it showed on the target as well. It might act differently in warm weather and/or a different combo.

This is exactly what I found last Winter testing loads at 400 yards.

Loads worked up in 40-70 temps didn't do so hot in the accuracy dept when it got below about -10F. They went from roughly MOA to 2MOA. Didn't see much of a difference from about 10-50F. Powders tested were H4350, R17 and H4831SC. H4831SC actually performed the best, very little if any loss of accuracy/POI.

Which is one reason a lot of my cold-weather hunting rifles are loaded with H4831SC.

FMAO, with the firearm and ammo:

Thinking -0 Montana wind chills, versus my my puny minus 10 & 20 windchills here.............
.............you da' man, !

I got to go warm up my 'creaking' parts very often when I do it from the bench. Yes, cold/or hot rifle and ammo, some real surprises sometimes. The surprise can be good or, not so good.