Rl26 Temp and Velocity correlation

[SkyScrapin]

Some say there is a measurable difference when compared to Hodgdon’s more temp stable powders. Unfortunately I’m getting about 200fps more velocity with Rl26 which provides for a meaningful difference in ballistics for me. Unfortunately, this is a hunting rifle and here in Texas, I’m not able to measure the variances of say, 20F 60F and 95F deviations and impact on velocity.

Anyone Successfully calculated these increased velocity curve for rl26? Example would be .8 FPS per Degree F

 

[straightshooter1]

Some say there is a measurable difference when compared to Hodgdon’s more temp stable powders. Unfortunately I’m getting about 200fps more velocity with Rl26 which provides for a meaningful difference in ballistics for me. Unfortunately, this is a hunting rifle and here in Texas, I’m not able to measure the variances of say, 20F 60F and 95F deviations and impact on velocity.

Anyone Successfully calculated these increased velocity curve for rl26? Example would be .8 FPS per Degree F

A while back, I picked up a chart dated May of 2018 showing its sensitivity to be ~.5 fps per degree. But, like with any powder, I feel sure it'll vary from lot to lot.

I don't recall the source and wish I had recorded that to share.

 

[918v]

It’s easy to freeze some rounds and heat some rounds and check it for yourself. Except that you will prolly blow primers with your 200 FPS higher load in a hot environment.

 

[Steel head]

I’ve found if pushed hard R26 has about a .45 or higher ratio but when I toned it down a bit it’s more like .30ish.
I’ve seen a similar phenomenon with H4350 with reasonable pressure giving excellent temp stability.

I’ve shot a lot of R26 over the last year and it has pretty decent temp stability, certainly nothing like R17 or the many other Reloader or non extreme Hodgdon powders.

You can keep a few rounds in a cooler and lay some on a hot shooting mat and measure them pretty easily.