Powder sensitivity chart

[para1505]

Would someone please tell me how to understand this char

 

[Codiekfx400]

Well the burn rate is from fast (top) slow at the (bottom). Then some of the powders have a number associated with them that is the temperature instability factor. The lower the number the less sensitive that powder is to air temperature fluctuations.

 

[Steel head]

I’m curious if the number is FPS per degree?
Never mind.
Actually it says it is fps per degree at bottom of chart.
Too bad 4451, R16, R23 and R26 are not listed or have temp value.
The R17 value seems exactly what I’ve found with it.

 

[Deleted member 113831]

I wouldn't take that chart as gospel. The fps per degree increase changes upon the case capacity ( e.g. H4350 will produce a very different result in 30-06 or 300 Win than in the 6.5 Creedmoor)

 

[260284]

I’m curious if the number is FPS per degree?
Never mind.
Actually it says it is fps per degree at bottom of chart.
Too bad 4451, R16, R23 and R26 are not listed or have temp value.
The R17 value seems exactly what I’ve found with it.

Powder Review: Alliant RL-16 - The Truth About Guns

Next Post▶ When I first dipped a toe in the reloading pond, I started by concentrating solely on rifles, specifically bolt guns. At this point, I see no reason to stray as I don’t shoot the volume to justify a handgun- or shotgun-loading habit, and my accuracy in both categories certainly...

www.thetruthaboutguns.com

I have had similar results with Rl16 from 20-104 degrees.

 

[Steel head]

Powder Review: Alliant RL-16 - The Truth About Guns

Next Post▶ When I first dipped a toe in the reloading pond, I started by concentrating solely on rifles, specifically bolt guns. At this point, I see no reason to stray as I don’t shoot the volume to justify a handgun- or shotgun-loading habit, and my accuracy in both categories certainly...

www.thetruthaboutguns.com

I have had similar results with Rl16 from 20-104 degrees.

In my 260 shooting R16 from 20 to 85 degrees I found I just don’t have to dick around at all with accommodating velocity swings.

 

[chevy_man]

Primers can have quite the effect on temp stability also.

I've found living where it's below freezing 5 months a year that a hot enough primer for the powder and volume helps when it's cold.

 

[cropdude]

Primers can have quite the effect on temp stability also.

I've found living where it's below freezing 5 months a year that a hot enough primer for the powder and volume helps when it's cold.

I agree on running a magnum primer especially with high volume slow burning powders, but that is mainly for uniform ignition and an even burn. This in turn should help lower the velocity ES and SD, but am unclear on how it can increase/decrease the actual "stability" of the powder?

 

[chevy_man]

I agree on running a magnum primer especially with high volume slow burning powders, but that is mainly for uniform ignition and an even burn. This in turn should help lower the velocity ES and SD, but am unclear on how it can increase/decrease the actual "stability" of the powder?

I've seen hang fires or really wide SD's when the primers on the edge of too cold. Works fine at 70*, but doesn't work at 0* type of situation.

It's not that the powder is inconsistent, it's just harder to ignite when it's all extremely cold.

 

[seanh]

Would someone please tell me how to understand this charView attachment 7258185

Where can a copy of that chart be found? When I open it up from the provided image it's blurry