Powder Stability.

[backwoods83]

I have been collecting data on my own, from accurate shooter, 24hr campfire, snipers hide, AR15.com, sniper central, etc.. most of it is my test. The moderators are welcome to make it a sticky and anyone can feel free to add. Since the topic comes up on a regular basis I figured I would post up a powder sensativity thread on all the data I've collected, it will be from fastest to slowest in fps per degree of temperature change.

HS-6 1.21fps per *
H110/W296 1.24 fps per *
Imr4227 1.17fps per *
Lil' Gun 1.31 fps per *
RL10x .71 fps per*
Benchmark .44 fps per *
Imr3031 .73 fps per *
Imr8208xbr .59 fps per *
H4895 .23 fps per *
Alliant Varmint pro .89 fps per *
Alliant AR comp .77 fps per *
Varget .19 fps per *
W748 1.32 fps per *
Imr4064 .53 fps per *
Ramshot Tac .91 fps per *
Imr4895 .87 fps per *
AA4064 1.11 fps per *
AA2520 .98 fps per *
RL15 1.52 fps per * from 50* and up
PP2000MR .99 fps per *
Imr4320 1.32 fps per *
Ramshot Biggame .98 fps per *
H380 1.44 fps per *
VV N150 1.08 fps per *
H414/W760 1.42 fps per *
Imr4350 .64 fps per *
AA4350 .47 fps per *
H4350 .29 fps per *
RL17 1.42 fps per *
Hybrid 100v .78 fps per *
RL19 1.61 fps per *
VV N160 1.24 fps per *
Imr4831 1.19 fps per *
Ramshot Hunter .86 fps per *
H4831 .36 fps per *
RL22 1.71 fps per *
Imr7828 1.36 fps per *
Magpro 1.01 fps per *
H1000 .21 fps per *
RL25 1.59 fps per *
Ramshot Magnum .87 fps per *
Retumbo .49 fps per *
RL33, still trying to get my data for this one.
US869 1.68 fps per *
H50bmg 1.64 fps per *

Feel free to add at any time, and remember that load density and primer type also effect these numbers, these are only to give you a ballpark figure. Info like this helps me when I'm using my ballistics calculator so I decided I would spend a few minutes to share it. Happy shooting.

 

[FAL Shot]

My "workhorse" powders are H4895, Varget and H4350. They work great in all normal non-overbore modern rifle cartridges. I see they are about the most temperature stable on the list.

Stick powders derive their temperature stability mainly from their shape, while ball powders use a retardant coating. Ball powders leave more residue in the barrel because of the retardant coating, at least the kind that is harder to clean out. That has been reduced somewhat by modern retardant coatings that burn off as they are being deposited. Then there are the copper fouling eliminator powders such as CFE 223 which I hear is very temperature sensitive.

Stick powders are inherently more temperature stable to begin with. For easy metering and copper fouling elimination some have gone to ball powders. The best copper fouling eliminator I know of is a chrome lined barrel polished to a mirror finish. I can shoot 200 rounds through an FN FAL or AR-15 with a military chroime barrel and have a very easy job of getting out the copper, and not much copper or carbon residue is there to begin with. Beside that, there is one FN FAL in Texas named Old Dirty that has gone at least 14,000 documented rounds with no cleaning whatsoever and it still functions flawlessly.

While ball powders give a more consistent powder charge when thrown from a powder measure, the better temperature stability of stick powders will more than swamp out that advantage under conditions of wide temperature swings. It only takes a few seconds to trickle up a charge, so I see no reason to use ball powder just because you can throw accurate charges quickly, except for high volume pistol ammo shooting in a progressive press.

It would be hard to imagine anybody interested in long range hunting using a progressive press to load ammo or to use a temp sensitive ball powder just because it throws quick accurate charges and saves them 15 seconds of trickle up time.

I saw no instance on the list where a ball powder matched the best stick powders in temperature stability. The only ball powder I possess is in surplus military ammo. It suits the US military requirement of 4" groups at 100 yards.

 

[backwoods83]

I have CFE223 but have not had a chance to do any temp test and have not been able to find any elsewhere, I have done a little velocity testing and it seems to be the ticket to run 55grn bullets upwards of 3900fps in a 22-250 without hurting the cases.

I also left H322 and H335 off the list as I do not use them, when loading bulk 5.56 ammo I just throw H4895 to within a tenth. Like you stated I doubt anyone is using those 2 for anything at any major distances.

I also do not have any data on BLC-2, N133, N135, N140, N540, N550, N165, N570, AA2015, AA2200, AA2460, LT32, I don't have much data on pistol or shotgun powders either but this is Longrange Hunting!

 

[clambdin]

Very good info ! I was surprised AA4350 held up as well as it did....and I thought Ramshot Magnum might be a little more stable than your results I have used a ton of it and it seems to be a little closer to the extreme powders..I might have to use more AA4350 it is easy to get and cheaper than Hogdon and IMR..

 

[backwoods83]

Ramshot Magnum tightens up stability wise when the load density is over 98% and you use the hottest primers. 100% density with Fed215Ms gets it closer to .65fps, that's only 65fps with a 100* temp swing, even at .87 that's only 87fps so its not as bad as it seems. The powders over 1.2fps are the ones that always get the complaints, mostly Alliant powders and oldschool ball powders, but the newer Alliant powders are getting better and the Ramshot/AA ball powders are pretty stable.

 

[clambdin]

Yeah I'm running Magnum mostly in 300 Win Mag with a high load density and 215 M primers .65 seems more like what I see..

 

[Niles Coyote]

I have often wondered how much difference the caliber, bullet weight used and load density plays into this as my numbers for varget were much closer to .6 fps per degree in my 308 with 175's and I have seen data that shows AR-Comp to be less than half that also in a 308...

 

[backwoods83]

The pattern I've noted with all powders, is that the numbers get the tighest with high load densities and a hotter ignition. In your case with the 308 and 175s, if you are running 42 or so grns of AR comp and 43.5grns or so of Varget, both with CCI BR2s your temp spread as well as possibly your extreme spread will likely tighten up with 43+ grns of AR Comp and 45+ grns of Varget with Fed210Ms or even more so with WLR primers.

 

[Pdvdh]

Here's three powders in three different cartridges. Velocity was recorded over duplicate chronographs (Oehler 33 & Pact PC2) or triplicate chronographs (Oehler 33 & Pact PC2 & Oehler 35P) run concurrently with each bullet fired.
Tract 1 is Retumbo in a 7mm Rem Mag with a 168gr Berger VLD. Barrel length = 24 3/8".
Tract 2 is IMR 7828 in a 300 Win Mag with a 210gr Berger VLD. Barrel length = 25 1/2".
Tract 3 is H1000 in a 280 RCBS Improved with a 162gr Hornady Amax. Barrel length = 28".

I know the Retumbo speeded up as the temperatures dropped to freezing ~32*F. Don't ask me why. Best I can figure is they've treated the Hodgdon Extreme powders to increase burn rate as temperatures fall. In this case MV increased with this lot of Retumbo with decreasing temperatures.

Notice the big differences between the two Hodgdon Extreme powders and IMR 7828.

 

[backwoods83]

That's good info, the Retumbo is almost spot on with my results, and the 7828 is close, that is weird with the H1000 though, but they have had a few mixed up batches of Varget, H1000, and Retumbo.

 

[North Idaho Hunter]

has anyone had a chance to test reloader 22? I was only able to test it from 90* down to 50* that gave me a MV variation of .57* per FPS.

 

[mechengr]

4 year old thread... But he's got RL22 listed in the first post at 1.71 fps/deg. I did some recent testing in my 280 Rem and between 32° and 75° I got 1.68 fps/deg. Might want to check your math, you should end up with units of fps/deg. You have deg/fps listed instead. Flip the units and that gives you about 1.75 fps/deg. Right in line with his data point as well as mine

 

[Clucknmoan]

Tag

 

[LDHunter]

backwoods83,

It would be much more useful in my opinion if you would sort and list these powers in order of sensitivity.

$bob$