Powder temp sensitivity chart

[Dave M.]

I’m looking for the temp sensitivity (ie fps/deg). I’ve seen an old chart dated 2018 but nothing more recent.
Specifically I’m curious about the following powders:
RL-15
RL-16
Viht N135
Viht N140
Viht N150
Varget
H4350

Thanks for your help guys.

Dave

 

[SeabeeKen]

Perhaps the manufacturers have some current info. I contacted Western Powders several yrs ago with that question and the answer I got was temp stability is a relative thing.

 

[gunsandgunsmithing]

Dave, keep in mind that while fps is easiest to measure, I believe there are several factors that can affect the pressure curve beyond strictly the end result of muzzle velocity. In other words, the bullet can leave the bbl at the same speed but not necessarily in the same time. I think this is the real factor here because tuning, by whatever means, is about timing bullet exit to optimal muzzle position. I'm not saying fps is irrelevant but that in bore time is the trick, much more so than the end velocity...fwiw.

 

[Dave M.]

Dave, keep in mind that while fps is easiest to measure, I believe there are several factors that can affect the pressure curve beyond strictly the end result of muzzle velocity. In other words, the bullet can leave the bbl at the same speed but not necessarily in the same time. I think this is the real factor here because tuning, by whatever means, is about timing bullet exit to optimal muzzle position. I'm not saying fps is irrelevant but that in bore time is the trick, much more so than the end velocity...fwiw.

I agree Mike. Which generally explains why RE-15 can have one of the largest temperature swings per degree F, but yet it shoots lights out in most Dasher rifles from 30-100F.
I was just curious if the updated info was out there and available.

 

[gunsandgunsmithing]

I agree Mike. Which generally explains why RE-15 can have one of the largest temperature swings per degree F, but yet it shoots lights out in most Dasher rifles from 30-100F.
I was just curious if the updated info was out there and available.

Been aiming to call you. I'll give you a shout soon. Just trying to catch up on orders and it's been crazy busy for a while now. I do look forward to talking with you again soon, my friend.

 

[Straightshooter1]

I’m looking for the temp sensitivity (ie fps/deg). I’ve seen an old chart dated 2018 but nothing more recent.
Specifically I’m curious about the following powders:
RL-15
RL-16
Viht N135
Viht N140
Viht N150
Varget
H4350

Thanks for your help guys.

Dave

Is this what you had in mind?

 

[Dave M.]

Is this what you had in mind?

View attachment 1511839

This is nice but it’s a relative burn rate chart. I’m looking for the amount of sensitivity in for per def F of change.

 

[Dave M.]

Been aiming to call you. I'll give you a shout soon. Just trying to catch up on orders and it's been crazy busy for a while now. I do look forward to talking with you again soon, my friend.

Always Mike. You are a true gentleman and the fixtures I drew up that you made for me are working top notch. Bless you brother. Stay safe.
Dave

 

[gunsandgunsmithing]

I hope I'm wrong but I think you need something that's simply not out there and has to be established individually due to the many factors involved. Especially so, if you wanna get into actual in bore times.

 

[gunsandgunsmithing]

You can pretty easily test things on a basis of energy per tenth of gr kinda thing and then chart them out over temps but it'll take some time, ammo and bbl life. I think things like powder characteristics in a given case will change enough to skew whatever you may find, but again, I hope I'm wrong. I'm sure you've seen heat charts. Not burn rate but heat. I mentioned this somewhere but bbl expansion gets overlooked in terms of bbl life. I think it may be more significant than anything, over time....expansion/contraction with heat on top of that.

 

[Florida Wally]

Try this thread. It is a good study and documented well.

Temperature Sensitivity of 11 Powders for .308 Winchester

The following are data and figure panels from a study I am completing on temperature sensitivity of 11 powders to load .308 Winchester cartridges with 168 grain BTHP bullets. The data may be useful to others. Powder shortages and previous tests for optimal match bullet powders have left me with...

forum.accurateshooter.com

 

[Dave M.]

I hope I'm wrong but I think you need something that's simply not out there and has to be established individually due to the many factors involved. Especially so, if you wanna get into actual in bore times.

I’ve seen other charts that state RE-15 is approx 1.5fps/deg and H4350 is approx 0.3fps/deg, I’m just wondering what others have found and if it correlates to what I’ve seen and recorded in my testing.

 

[Dave M.]

Try this thread. It is a good study and documented well.

Temperature Sensitivity of 11 Powders for .308 Winchester

The following are data and figure panels from a study I am completing on temperature sensitivity of 11 powders to load .308 Winchester cartridges with 168 grain BTHP bullets. The data may be useful to others. Powder shortages and previous tests for optimal match bullet powders have left me with...

forum.accurateshooter.com

This is exactly what I was as looking for. Wish a couple other key powders were included in the testing.

 

[RabbitSlayer]

I attached a chart that has some of those powders. There is another one floating around too and that one is extensive and has a lot of ball powders on it. Keep googling you will find it eventually. Its in a forum.

 

[Rick300]

I found this one. I'm not sure how old it is

 

[Dave M.]

I attached a chart that has some of those powders. There is another one floating around too and that one is extensive and has a lot of ball powders on it. Keep googling you will find it eventually. Its in a forum.

Very cool info. Awesome read.
Dave

 

[RabbitSlayer]

I found this one. I'm not sure how old it is

View attachment 1511885

Thats the one l was thinking of

 

[jxb]

Hodgdon lists that info for some of their brands and powders. Both Varget and H4350 are part of their extreme lineup which for all intensive purposes are temp insensitive to something like 122f and only 1% or some silly low number at that end of the range. I've shot H380 for decades, now there's a powder that is definitely not temperature insensitive.

https://hodgdonpowderco.com/wp-content/uploads/2023/04/hodgdon-extreme-series-powders-test-results-for-temperature-sensitivity-1.pdf

I just wish they would update it, 2012... really?

 

[Acyr]

This is exactly what I was as looking for. Wish a couple other key powders were included in the testing.

My own testing of N150, N140, Varget and H4895 mirrors BillC79's excellent work.

 

[6.5 forever]

I remember a chart which listed 4 Hodgdon powders. H4350 was the least affected by temperature. This was a actual test