by .458 ruger shooting .458 win in the .458 lott chamber does well with imr 3031. Ive been working up loads in the 30-45 degree temprature range.. Will I start to have accuracy problems with excess pressure when the temps rise into the 80s,90 this summer and to what extent have you noticed? A winter and summer load would be acceptable i guess, but could it be a bigger problem than that? thanks dave

I have tested IMR 3031 in cold, about 45*F, and hot, about 100*F, and the velocity change was HUGE, on order of 200fps.

IMO, 3031 is NOT a suitable 458wm powder for several reasons, fist being that it produces relatively low velocity for pressure (with heavier bullets, no experience with lighter bullets) and second the temperature change.

If I were you, I would be looking at AA2230 for 450 and 500gr bullets and H4895 for 450 and 400gr bullets.

There is another powder, can't remember which, which is supposed to be marginally better than AA2230 for heavy bullets.

BTW, H 4895 is in Hogdon's extreme line, which develpoped for temperature insensitivity for Aussie defense forces. My testing confirms little, if any, velocity change due to temp delta.

My testing also revealed little or no velocity delta for AA2230. What there might have been was obscurred by round to round variation.

500grs and 2150fps is possible with AA2230.

JPK

Though my experience is not with this powder nor a 458, it is with another IMR powder (7828) and my 338-378 Wby. Same experience as JPK. Large variation in velocity between 70 degrees and 100+ degrees here in the desert.

I would imagine that H322 or H4895 might be a better choice as they seem to not be too temperature sensitive. I'll be trying H1000 for the Wby soon as a few other people I know say it works very well with varying temperatures.

Ken....

There are one or two of the Hodgdon "Extreme" powders that are relatively temp insensitive that would work well in the 458's...check out the Hodgdons manuals...I've tried H4895, Varget, Benchmark, H322(all Extreme powders) in my 45-70, 45-90, and 458 WM with bullets from 300 to 525 gr jacketed and hard cast lead...I pick the powder the shows the best accuracy/pressure/ velocity ratio for a specific bullet...Varget and H4895 seem to full that bag, along with AA2460...check with the loading manuals and pick a better powder...I never had any use for a "summer/winter" load...way too many variables to cause trouble.

AA2460 is the "other" powder...the burning rate/pressure between it and AA2230 are very close and it works well in the 45-70 and -90...you just have to do your homework and the testing required to work out which powder(s) are best suited for what bullet weight you are shooting.

You can check with Johan Lobser at Accurte Arms Powder co for specifics with your cartridge...you need the COAL, the H2O capacity with seated bullet, bullet weight and brand, cartridge case and brand ready to send to him.

Luck with your quest.

Ive been calling powder companies and aa powders are not extreem extruded(temperature insensitive) nor is tac, the aa tech did not think reloader powders were either to his knowledge but was not sure.. Who makes xmr 2015 and exterminator? so i can call them.. thanks dave. foobear benchmark is just a little slower than the two poweders you listed and is etreemly extruded..h322 is not extreemly extruded..

I missed something...look in the Hodgdon manual...it states those powders as "Extreme" powders meaning they all work very well at temp "extemes"...it doesn't have anything to do with whether it is a ball or extruded powder...

The Alliant Reloader series ISN'T considered to have as wide a temp range as the Hodgdon Extreme powders, nor is AA powders...and each powder has a specific range of temps it works best in...powders are NOT all created equal...

The "Extreme" nomenclature is a Hodgdon publicity gimick...But well proven to work...

I'm not understanding your use of "extreemly extruded"...the "Extreme" powders include both ball AND extruded powders.

Benchmark is just below 3031 on the burn rate chart...slightly faster than AA2230, H4895...Varget is a few steps slower...

XMR2015 is an older designation of Accurate Arms powder now called AA2015.

X-Terminator AND Tac powders are made by Ramshot who now owns Accurate Arms powders.

You can find booque information by searching the different powders on the internet.

Luck on your projects.

foobar, you are 100percent correct, it says extreem right on the bottle, but was omited in the 2008 hodgdon annual manuel descriptions of the powders. I thank you for correcting me, becouse im needing powders to make my gun work, and i want the extreem variety for obvious reasons.. thanks dave

You will get, on average, a change of three (3) feet per second of velocity for every one degree F. change in temperature.
So a 50 degree temperature increase from 30-45 degrees to 80-95 degrees will increase MV by about 150 FPS.
This is a big increase of speed and pressure in the 458 Win.
Sincerely,

From WHAT powder Virginia Creeper???

I'm not doubting what you say but it is a general statement without a powder designation and could be misconstrued. I've seen charts that show the velocity/temp variations of different powders and it can get fairly wide depending on the type of powder.

You can go to the Hodgdon site and see the temp variation vs powder for some of the powders, or at least used to...but you can still go online to find that information.

I don't have the 2008 Hodgdon manual yet, but the 2006 manual lists the powders on page 59-61.

Luck on your projects.

The 3031 with a 35 degree temp increase gave me about 100 fps velocity increase, then the third round heated up in the chamber and gave me anouther 50-80 fps, ruining groups, and sending that shot down due to less barrel time.. Im done with 3031, and am haveing good luck with h 4895.. Very consistent, but need to work up the loads further.. dave..

3031 will make a bullet go out the barrel of a 458 , but H4198 ,H4895, and maybe Varget , I havn,t tried it yet are very good 458 powders .. I should have got with the program and chronographed @ -60 F this past winter .. Maybe next winter ......

Now , don,t use this load and blame me if it doesn,t work the way you want , ..But I built up a 400 gr 458 Win mag load in the winter @ False Is . some time ago useing 80 gr AA 2230 and 400 gr X bullets 400 gr Barnes Orig. and 400 gr Kodiak Bonded Core rn . bullets .....I was chronographing 2410-2420 fps and every thing looked great ..... The next summer w/ temps in the 80s I decided that load was too hot and backed off 1 grain and got 2380 fps .. That is the load I still use in the 458 with 400 gr bullets ... I have no idea what that load would in warmer wx....I use mag primers ......

In answer to FOOBAR's question...From WHAT powder Virginia Creeper???

Let me add this detail to my prior post. Since the subject was IMR powder 3031 and the title of the Post is "imr 3031 and temp change", I was writing about IMR 3031.
Sorry not to be clear.
Sincerely,

quote:

Originally posted by Virginia Creeper:
In answer to FOOBAR's question...From WHAT powder Virginia Creeper???

Let me add this detail to my prior post. Since the subject was IMR powder 3031 and the title of the Post is "imr 3031 and temp change", I was writing about IMR 3031.
Sorry not to be clear.
Sincerely,

Thanks for the clarification. That you were refering to IMR 3031 was lost on me as well, since a whole handful of powders were mentioned prior to your post.

Your 3fps/degree almost perfectly matches my experience.

JPK

quote:

Your 3fps/degree almost perfectly matches my experience.

JPK

So, it is my turn to ask the question put to me by FOOBAR.
From WHAT powder JPK???
Sincerly,