Powder Temperature

[Conaso]

I use Strelok ballistic app and have powder temp turned off. When I chronograph my load I record the zeroing weather, i.e., temp, barometric, and humidity. I use purportedly temp insensitive powders, e.g. H4350, H322, etc.

How am I to obtain powder temp, practical testing 80 and 40 degree temps and re-chrono the loads?

 

[Shippj]

Put one (or a couple) rounds in the freezer, take the temp of the rounds before you shoot it and capture the velocity Put one (or a couple) on the dash, take the temp of the rounds before you shoot it for velocity. Graph the velocity results in correlation to the temperature.

 

[LawnMM]

Or you could just shoot and record the temps as you (if you even) encounter them ??‍

 

[Sticks]

Been there done that. I don't know that simply changing the powder temp makes the difference.

I did some testing with ammo at 20* at the range, and 160* on a 50* day. Ammo was soaked in those temps for 3+ hours prior to shooting 10 fps between the high and low temp ammo in 4 flavors of powder...including the super temp sensitive CFE.

 

[Conaso]

First off, I don't compete and don't have a range beyond 100 yards. So the nuance of powder temperature is wasted on me. But, being retired, I have a lot of time on my hands. Just trying to understand the complexity of exterior ballistics.

If powder temp is such a factor in LR, or any shooting, one would think a table exists or the manufacturers would provide info, like BC, on the powder sensitivity factor. Then someone can just select the powder used, e.g., H4350. Expecting people to freeze and thaw bullets is ridiculous. Just because the ambient temperature is 84 degrees doesn't mean the powder is 84 degrees.

Just saying...

If someone could direct me to an online reference so I could educate myself, I would be most appreciative.

 

[Conaso]

Well, I did some research (Precision Rifle Blog) and found H4350 changes .21fps for every 1 degree F. So, a velocity of 2793fps at 81 degrees down to 39 degrees the temp change would result in 11fps. I think I will keep the powder temperature feature turned off!

 

[Timo Turl]

First off, I don't compete and don't have a range beyond 100 yards. So the nuance of powder temperature is wasted on me. But, being retired, I have a lot of time on my hands. Just trying to understand the complexity of exterior ballistics.

If powder temp is such a factor in LR, or any shooting, one would think a table exists or the manufacturers would provide info, like BC, on the powder sensitivity factor. Then someone can just select the powder used, e.g., H4350. Expecting people to freeze and thaw bullets is ridiculous. Just because the ambient temperature is 84 degrees doesn't mean the powder is 84 degrees.

Just saying...

If someone could direct me to an online reference so I could educate myself, I would be most appreciative.

The lot to lot variance makes a table imperfect, or at least that’s what Applied Ballistics guys told me.

Below is factory Prime ammo tested all on a single day...the velocity change is noticeable:

PRIME 130gr
Temperature (F): 42
Density Altitude (Ft): -380
Velocity FPS: 2882
Standard Deviation: 14

Temperature (F): 45
Density Altitude (Ft): -740
Velocity FPS: 2911
Standard Deviation: 10

Temperature (F): 54
Density Altitude (Ft): -260
Velocity FPS: 2910
Standard Deviation: 15

Temperature (F): 62
Density Altitude (Ft): 257
Velocity FPS: 2921
Standard Deviation: 15

Temperature (F): 78
Density Altitude (Ft): 1360
Velocity FPS: 2935
Standard Deviation: 12

 

[spife7980]

I did a test of my own a couple years back- 6xc 24" 105 rdf H4350 and RL 16 in the cooler on ice 35°, normal in the shade 85°and left in the sun 120°.

Came out to .73 fps/° for H4350. Not every combination will give the same results so the onus is really on you to observe what is happening yourself. Be it by waiting for the condition to see or deliberate recreation. There is a change.

 

[steve123]

Depending at what velocity the middle of the node is and temp - more specifically the time of year I worked up the load, I add or subtract a 10th grain of powder to compensate a little. Keep in mind I'm a fair weather shooter, no brain cooking going on or freezing my ass off either so.....!

 

[918v]

Been there done that. I don't know that simply changing the powder temp makes the difference.

I did some testing with ammo at 20* at the range, and 160* on a 50* day. Ammo was soaked in those temps for 3+ hours prior to shooting 10 fps between the high and low temp ammo in 4 flavors of powder...including the super temp sensitive CFE.

I did this test on PP2000MR and saw the same thing, BUT I think it depends on the totality of the components.

I read somewhere that CCI250 primers are more sensitive than FC215’s. So maybe the primer has something to do with it.

In my test I used FC210’s with 48grs of 2000MR in FC brass with Berger 175’s @ 2.805” OAL. The average velocity did not change, but the ES got crazy with the hot ammo.

 

[plamia2]

[QUOTE = "Конасо, должность: 7797918, участник: 54853"]
...
Как получить порошковую температуру, провести практические испытания при температуре 80 и 40 градусов и провести повторную хронологическую нагрузку?
[/ QUOTE]

?

 

[sako17]

I'm no powder expert. I do believe powder "sensitivity" is more marketing gimmick than reality. I've killed big game at freezing temps and a shirt sleeve elk rut hunt. Temps didn't affect accuracy.

There's an old fishermen saying: fishing tackle is designed to catch fishermen. I can trout fish the Western USA with a half-dozen lures. I can offshore fish for big tune with a couple. I learned the expensive way: I have tackle boxes full of stuff that has never touched water.

I'm new to predator/small game hunting. I've bought a pound of IMR-4198 for my brand stanking new Triple Deuce. I have a feeling it'll be the only powder I'll need. I can load my big game rifles with only H-4831 & be content.

Just my opinion, and I ain't a powder expert. I merely know what works.

 

[GIXXER2000]

I live in NW AZ and i have a winter and summer load. Temps in the coolest part of winter are 45 to 60 but in summer its 90 to 120 depending on time of day i can get out and shoot. This does affect velocity even in the temp stable powders.

 

[Shippj]

I'm no powder expert. I do believe powder "sensitivity" is more marketing gimmick than reality. I've killed big game at freezing temps and a shirt sleeve elk rut hunt. Temps didn't affect accuracy. There's an old fishermen saying: fishing tackle is designed to catch fishermen. I can trout fish the Western USA with a half-dozen lures. I can offshore fish for big tune with a couple. I learned the expensive way: I have tackle boxes full of stuff that has never touched water. I'm new to predator/small game hunting. I've bought a pound of IMR-4198 for my brand stanking new Triple Deuce. I have a feeling it'll be the only powder I'll need. I can load my big game rifles with only H-4831 & be content. Just my opinion, and I ain't a powder expert. I merely know what works. Powder temperature sensitivity is not snake oil. It is a very measurable and does affect the point of impact. It may not effect your "minute of elk", but it does effect ballistics enough that for those concerned with their shot placement that we measure it and account for it.

 

[Jimgal62]

Precisionrifleblog.com did a test on powder sensitivity.

You should search for that article for the results and how the experiments were conducted.

Good read.