RL26 temp sensitivity

Flyjunky

WKR
Joined
Jun 22, 2020
I’ve seen it talked about numerous times on multiple forums about Rl26 being sensitive to temps, especially higher temps.

This past weekend I was listening to a Hornady podcast about powder temp sensitivity while I was working on the computer.

They said that Rl16, Rl23, and Rl26 were some of the least sensitive powders they have ever tested. From -20° to 125° it had very little change.

We use 26 in multiple different cartridges, with hunts ranging from mid 80’s to the teens and have seen exactly what Hornady found. Even range sessions in summer and winter were very consistent at distance.

Just thought I’d pass this along for those who may also use 16 and 23.
 
I knew 16 and 23 were supposed to be extraordinary - better than hodgdon extreme powders. Have not heard the same about 26.
 
I knew 16 and 23 were supposed to be extraordinary - better than hodgdon extreme powders. Have not heard the same about 26.
Neither had I even though our shooting had demonstrated as such. It was good to hear the Hornady tests showed the same.
 
Maybe I’m the oddball here, but I don’t get the relevance of temp sensitivity. If a powder is consistent and works well for the application, just account for the difference in velocity.

There are numerous ballistic solvers that account for temperature. The 4DOF app even has some powders listed with their temp stability number. The GeoBallistics app allows you to input different velocities based on ambient temp.


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Maybe I’m the oddball here, but I don’t get the relevance of temp sensitivity. If a powder is consistent and works well for the application, just account for the difference in velocity.

There are numerous ballistic solvers that account for temperature. The 4DOF app even has some powders listed with their temp stability number. The GeoBallistics app allows you to input different velocities based on ambient temp.


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I won't use a temp sensitive powder for hunting. I've been on hunts a long ways from home where it's ranged from the teens to the 90's. I don't want to have to solve for that when there are options out there that don't require such gymnastics. Plus, temp sensitivity can be unpredictable.
 
I won't use a temp sensitive powder for hunting. I've been on hunts a long ways from home where it's ranged from the teens to the 90's. I don't want to have to solve for that when there are options out there that don't require such gymnastics. Plus, temp sensitivity can be unpredictable.
Exactly. The fps/deg isn’t linear and even can change depending on cartridge….no thanks.
 
I won't use a temp sensitive powder for hunting. I've been on hunts a long ways from home where it's ranged from the teens to the 90's. I don't want to have to solve for that when there are options out there that don't require such gymnastics. Plus, temp sensitivity can be unpredictable.
Heck, I’ve never had it to be an issue with any supposedly temp sensitive powders.
 
I won't use a temp sensitive powder for hunting. I've been on hunts a long ways from home where it's ranged from the teens to the 90's. I don't want to have to solve for that when there are options out there that don't require such gymnastics. Plus, temp sensitivity can be unpredictable.
I can understand that. Do you use a ballistic solver for your shooting solution? If so, then why not just use one that accounts for temp stability of the powder? It doesn't require any extra steps that you're likely not already accounting for, if you are using a solver.
 
Maybe I’m the oddball here, but I don’t get the relevance of temp sensitivity. If a powder is consistent and works well for the application, just account for the difference in velocity.

There are numerous ballistic solvers that account for temperature. The 4DOF app even has some powders listed with their temp stability number. The GeoBallistics app allows you to input different velocities based on ambient temp.


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Temp sensitivity matters quite a bit when you do your load development in the winter when there isn't anything else going on, like I do. I've had instances where I found a good load, below pressure, in February/March that didn't pass muster in warmer weather. Haven't had those issues with RL23 or 16 fwiw
 
I can understand that. Do you use a ballistic solver for your shooting solution? If so, then why not just use one that accounts for temp stability of the powder? It doesn't require any extra steps that you're likely not already accounting for, if you are using a solver.
Mainly because I don’t believe the solver can figure temp sensitivity accurately. As flyjunky mentioned, temp sensitivity is not always linear, or predictable. I’ve seen cold do the same as hot. How can a solver account for that mathematically?
 
temp sensitivity is not always linear, or predictable

It would seem to be very dependent on basically everything involved.

I do my best to check my loads in the dead of summer, as much as that sucks, and then re-check them on the coldest day that I have the chance.
 
I can understand that. Do you use a ballistic solver for your shooting solution? If so, then why not just use one that accounts for temp stability of the powder? It doesn't require any extra steps that you're likely not already accounting for, if you are using a solver.
Even if a solver is perfect for ambient temperature correction, I don't see how a shooter can predict the temperature of a round loaded into a hot chamber. A non-temp sensitive powder is a better option if available.
 
Even if a solver is perfect for ambient temperature correction, I don't see how a shooter can predict the temperature of a round loaded into a hot chamber. A non-temp sensitive powder is a better option if available.
That round would need to sit in the chamber for a bit for it's temperature to adjust all the way through. It's possible, sure. My point is that I think we make a bigger deal out of temp stability than is necessary. @finner had a good point regarding pressure, and that I agree with, but in terms of hunting, how far of shots are you taking that 30-50fps is making that substantial of a difference.
 
That round would need to sit in the chamber for a bit for it's temperature to adjust all the way through. It's possible, sure. My point is that I think we make a bigger deal out of temp stability than is necessary. @finner had a good point regarding pressure, and that I agree with, but in terms of hunting, how far of shots are you taking that 30-50fps is making that substantial of a difference.
I’ve certainly seen triple digit plus variance.

Also, there comes a point in time where I’ve reached my personal limit on technology and mathematics factored into my hunting. Maybe that’s just also rhe bow hunter in me.

Do you ever load up all your crap in the morning to go hunting, stress out that you forgot something and long for the days when you just grabbed your rifle, a canteen slung over your shoulder and a candy bar in your pocket? Reasonable range, get a good rest, and shoot. No math, no little computers in our pockets, no weird reticles, no laser beams. Just hunt. There is a point of diminishing returns to all this crap and the thought it requires to use it all.

In my mind, with a temp resistant powder it’s one less thing to occupy brain space.
 

Do you ever load up all your crap in the morning to go hunting, stress out that you forgot something and long for the days when you just grabbed your rifle, a canteen slung over your shoulder and a candy bar in your pocket? Reasonable range, get a good rest, and shoot. No math, no little computers in our pockets, no weird reticles, no laser beams. Just hunt. There is a point of diminishing returns.

In my mind, with a temp resistant powder it’s one less thing to occupy brain space.
Sure, but I'm not taking long shots in that scenario either. Maybe 200 - 250. more than that I'm using a rangefinder and either a drop chart or solver. I know what the MPBR is for my different rifles and loads. 264yds is the longest MPBR. Shortest is 126yds (300blk). That's with a 10" kill zone.
 
Sure, but I'm not taking long shots in that scenario either. Maybe 200 - 250. more than that I'm using a rangefinder and either a drop chart or solver. I know what the MPBR is for my different rifles and loads. 264yds is the longest MPBR. Shortest is 126yds (300blk). That's with a 10" kill zone.
OK sure, at those ranges I will agree with you
 
I love the performance that RL26 provides. However, I have seen swings in velocity with large temp (and elevation simultaneously) swings. I had a load worked up at me in 80° temps @1250’ elevation at 3044fps over 30 round groups. I went to Raton,NM to shoot with temps in the 40s and my average velocity with the same loads was 3005fps.

That’s a pretty substantial difference.

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Mainly because I don’t believe the solver can figure temp sensitivity accurately. As flyjunky mentioned, temp sensitivity is not always linear, or predictable. How can a solver account for that mathematically?
This ^ exactly. I was convinced people were falsely claiming r26 temp sensitivity to reduce demand until I saw a higher pressure load go wild when left on truck dash with heater on to see velocity fluctuation.

My thoughts are r26 at sammi pressures has good temp stability, but at higher pressure where most people run fairy dust temp sensitivity goes wild.
 
Mainly because I don’t believe the solver can figure temp sensitivity accurately. As flyjunky mentioned, temp sensitivity is not always linear, or predictable. I’ve seen cold do the same as hot. How can a solver account for that mathematically?

No but it’s better than nothing. If it’s 80% correct, that’s a marked improvement.

The Revic Binos have this feature built in if you select a powder from their library in the ammo section when building a profile.


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