Temperature sensitive powder

[piper]

recently I have been using RL22 powder in my 8mm rem., and Im getting very good velocity and accuracy, Now Im hearing that powder is quite sensitive to temperature, does anyone know much about this?

 

[sageadvice]

Piper, most of the loads that i develop, not all that many, i do so in the Summer. Personally, i want the most that i can get from my cartridge so i want them on the hot side. If they shoot thru my rifles during the summer when it's warm out, and still don't show signs of too much pressure, i feel safe hunting with them later on when it's cooler...buck season.

If a guy does the opposite, develope a loading when it's cold and shooting them when it's warm...bad things can and do happen.

Don't know about Reloader22 in particular, i just use this caution in all my loadings with all the powders that i use.

Joey

 

[hntbambi]

Yep, it's a known phenomena that occurs more with some powders than others. Typically, extruded powders are least effected whereas ball powders are more effected. I had some loads in my varmint guns using H380 that I had to back off a grain in the summer as the pressure was too high. There was no reduced velocity though, as velocity is a byproduct of pressure. I also had a load that shot great around 70? for my TC Contender in 45/70 but in cold temps (sub freezing) would leave 2-3 grains of unburned H322 (old version) powder in the barrel. I moved to 4198 and this fixed the problem.

Hodgdon's Extreme line of powders which are made in Australia are some of the least temp sensitive powders I have ever used. I still see some velocity variances over a 70? temperature swing, but not as bad as ball powders.

There are plenty of powders for us to choose from today that deliver outstanding velocity and accuracy.

 

[mtmuley]

If it bothers you, switch. I've been using "sensitive" Alliant powders for ten years now. Only problems I've found are internet fodder. mtmuley

 

[piper]

I guess I should get up early when its cold and fire a few through the cronograph and see whats up. Its the internet fodder thats been bugging me. Thanks for the comments

 

[mtmuley]

I've got up early and fired a BUNCH into deer and elk. THAT is why the internet fodder does not bother me. If you look long enough, you will find another inadeqacy in your load to deal with. If it's accurate and kills game, use it. mtmuley

 

[sageadvice]

Piper, What Mtmuley is saying makes sense...as long you are well within the recommended loading limits listed in your reloading manual. As i mentioned above, my loadings are hot and using the manuals as a guide only, i start withing the suggested limits and keeping an eye on the chronograph, proceed upward in powder amounts until i'm seeing pressure signs. Sometimes, as in the case of my 280 AI, i can be "considerably" over the recommended dose of powder before i start to see these signs. I usually then back off a grain or so and load up a few batches of different over all lengths and see how well they group. I've had good success doing it just this way.

I shoot and hunt with one load that is 8 grains over recommended max in the Nosler book!

Personally, i wouldn't think of taking a load developed like this if it was developed in the winter, hunting or shooting during the hot summer. That's me...and the words of caution from my mentors speaking.

Joey

 

[piper]

LAST EDITED ON Mar-14-10 AT 07:05PM (MST)[p]Good advice, with 82 grains of RL22 and a 200 grain nosler I get about 3160fps, thats max in the book and I have no signs of high pressure in the summer. My concern was about how far velocity falls off in sub zero weather, I have shot game when its cold and no problem, but the shots weren't all that long,I was wondering about long shots being effected. The internet fodder about that type of powder being affected a lot by temperature changes caught my eye.

 

[eship]

Piper, I had the same concerns so I checked out Hodgdon's website which had some good information. In their example they used a 300WM with a 180GR. Sierra Boat Tail. Using RL-22 in 125*F. speed was 3,142fps. In 70*F. speed was 3,087fps. In 0*F. speed was 3,067. That's an extreme spread of 75fps, but only 20fps from 70*-0*. I imagine most of us hunt between the later two temps. Put the numbers into a ballistic calculator and see how it looks for the distances your considering shooting. Hope this helps.