Temperature sensitive powders

[Kelly Timoffee]

Has anyone ever come across documents or studies or tests that have been done on various powders to show the effects of extreme temperatures and the actual results of such??

I would like to do my own but that is ALOT of powder and test loads to go through.

 

[Boomer]

Yes, if you Google St Mark's powder you can see an explanation of how they test their line of Hybrid powder for temperature sensitivity. Essentially they airburst a large charge and measure the over-pressure, then compare it to the data collected from similar tests at higher and lower temperatures.

Edited to add . . .
Many powders which are designed to be temperature insensitive, are insensitive to heat, which is an important consideration if you hunt in Australia, Africa, or even the warmer parts of North America, but in the cold it doesn't seem to hold up to close scrutiny.

 

[fiddler]

This is an interesting topic. I know there are different effects of powders and their pressures at different temperatures just from my own shooting and how things group. I have no actual data to contribute, but loads that I can keyhole at 100 yards in warm weather does not do this in -25. I suspect some powders are more stable than others. I just don't know which ones, nor have the ability and time for such an undertaking to make this determination.

 

[Ron AKA]

Has anyone ever come across documents or studies or tests that have been done on various powders to show the effects of extreme temperatures and the actual results of such??

I would like to do my own but that is ALOT of powder and test loads to go through.

Hodgdon has published some results. See this link:

Hodgdon Extreme Powder Comparisons

One of the posters here, Kombayotch, has done testing which seem to verify that Hodgdon is telling the truth. keep in mind that Hodgdon also owns IMR and has nothing to benefit in making their powder look worse than it is.

 

[H4831]

I tend to think that temperatures affecting powder is over rated. Now, I didn't say there was no effect, I just said it is over rated by many of today's shooters.
Kelly, I grew up in the homestead days about 65 miles north east of where you live. Some of those years were mighty cold, probably colder than are current winter temperatures. The homestead people living in those bush covered boon docks supplied their families with wild meat and they hunted 12 months of the year.
In the coldest of weather, like 45 below zero, they simply aimed, their usually, 30-30 type rifles at where they wanted to hit a moose or elk, fired and killed the animal.
I've said it on these threads before, but the only precaution taken for cold weather shooting, was to clean the action, in particular the firing mechanism with kerosene, of every last trace of oil. In the spring they would reoil them. But the ammunition, CIL Dominion, worked just fine.
I reloaded for at least 35 years before I read about temperature effects on powder. My reloads were at least as heavy as any shown in any modern reloading book. I shot them in severe cold weather, as well as in the heat of July or August. If there was any difference in their performance, I failed to notice it.
Do I get excited about the temperature sensitivety of powder? No.

 

[NormB]

I tend to think that temperatures affecting powder is over rated. Now, I didn't say there was no effect, I just said it is over rated by many of today's shooters.
Kelly, I grew up in the homestead days about 65 miles north east of where you live. Some of those years were mighty cold, probably colder than are current winter temperatures. The homestead people living in those bush covered boon docks supplied their families with wild meat and they hunted 12 months of the year.
In the coldest of weather, like 45 below zero, they simply aimed, their usually, 30-30 type rifles at where they wanted to hit a moose or elk, fired and killed the animal.
I've said it on these threads before, but the only precaution taken for cold weather shooting, was to clean the action, in particular the firing mechanism with kerosene, of every last trace of oil. In the spring they would reoil them. But the ammunition, CIL Dominion, worked just fine.
I reloaded for at least 35 years before I read about temperature effects on powder. My reloads were at least as heavy as any shown in any modern reloading book. I shot them in severe cold weather, as well as in the heat of July or August. If there was any difference in their performance, I failed to notice it.
Do I get excited about the temperature sensitivety of powder? No.

All True,

But minute of Moose is one thing, hitting a 5"v bull at 1000yds consistently is another.

NormB

 

[H4831]

All True,

But minute of Moose is one thing, hitting a 5"v bull at 1000yds consistently is another.

NormB

Looks like you should read my post again.
Did I say that cold didn't effect the powder?

 

[Kelly Timoffee]

My thinking was , why would these manufacturers promote a product that when temperature changes the results would start becoming erratic. If I loaded a particular round that shot well at say +10C then used that same load at -15C and the accuracy and consistency went completely south how long would that powder actually still sell?I also do think that the effects of temperature on powder is well over exaggerated.

Less info on it out there than I expected.

Maybe once I become independently wealthy and with lots of time off I will take a 12 month holiday and experiment with these environmental changes on various powders.

 

[NormB]

Looks like you should read my post again.
Did I say that cold didn't effect the powder?

I got the gist of the post fine and I stand by my response

NormB

 

[Ron AKA]

One of the saving graces of reloading is that most work up their loads in warm weather, and shoot them in colder weather. Since velocity and pressure goes down they just under perform a little. The moose still dies. The risk starts to come in if you work up max loads in very cold weather and then try to shoot them in the heat of the summer, and after letting the cartridge sit and soak in a hot chamber first. Fortunately not many do that.

To target shooters it is a different ball game. Most are trying to keep the velocity in the sweet spot range to minimize group size. That becomes hard to do if the powder is jerking velocity all over the place. A temperature insensitive powder simplifies the exercise considerably. And, it is not just about outside temperature, but really the temperature in the case when you pull the trigger. Barrel chamber temperature has a large effect if the case soaks any length of time.

 

[B-78]

I did my own test 3 or 4 winters ago.A farmer was having trouble with coyotes in his cows and wanted them gone. He would feed silage to the cows every morning at the same time so when he drove in with the silage wagon the cows would get out of their beds, take a crap and then go eat some more. The coyotes learned to wait for the cows to leave and then go and eat the warm crap. Me and my partener would sit in a blind and shoot the coyotes as they came in but where 150 to 200 yds away.As we sat there some mornings for 2 hrs in -40C I noticed that I would start to miss the coyotes at the end but atributed this to being cold.A couple times I was sure I was holding dead on the center of the coyote although so I went home and did different test with my gun and ammo at different temperature. If I shot warm rounds in a cold gun my POI did not change but if I took -40C ammo and shot it the POI moved as much as three inches. The load still shot decent groups but the POI did move. I was shooting 35gr Bergers in my 204 with BL-C(2). I did the same test with H4895 and found the POI did not move hardly at all so I switched and have had no problems since then. I still use 40gr Vmaxs and BL-C(2) to explode gophers at long ranges but will not load it for hunting in the winter anymore.