Temp stable .270 wsm powder

[jdavistx]

That's a mighty cool looking table. Do you mind if I ask where it comes from, who generated it and how? Also what the two columns mean? I see the right side says something about 50 degree and up so left side is a larger temp range and right is moderate to high temp?

looks like the thing to do is just hold out for more h1000, maybe try re 23 if I stumble over it and if I cant find anything in time for my october hunt I'll set up a load for re 22 or retumbo and test it I'm temps that represent what I expect to see in oct.

I got the table from Predator Masters website and don't have the original source. All you have to do is Google up temp sensitivity for powders. The "50˚ and up" comment means the powder burn rate is non-linear under that temp so the estimate of 1.52 for RL15 under 50˚ is not accurate.

If you know the temp, you can enter that into your ballistics calculator via a MV/TEMP chart as a starting point. Then see what you get on the range. I'm not recommending a particular powder here. Just trying to help ppl understand the importance of factoring in burn rate over temp. If you know that, I think it helps a lot at long range under large temp variations.

 

[Hornhunter32]

Retumbo has worked well for me in a 22" 270 WSM with the 140 Berger Classic Hunter

 

[Buddro]

I see, I saw two columns that had the same powders in them and thought they were different but didn't look close. The left column is sorted in order of least to most affected, the right is sorted alphabetically. I thought at a glance the 50* comment was detonating that the two columns were different parameters.

 

[justdreaming]

While not the 140, to give you an idea for a shorter barrel, H4831sc @ 66.5gr, 130 Berger Classic Hunter out of a 16.75" barrel, I'm getting 2950.

 

[Lenny Foffa]

you may want to test a few using H4831SC

 

[new2mud]

I got the table from Predator Masters website and don't have the original source. All you have to do is Google up temp sensitivity for powders. The "50˚ and up" comment means the powder burn rate is non-linear under that temp so the estimate of 1.52 for RL15 under 50˚ is not accurate.

If you know the temp, you can enter that into your ballistics calculator via a MV/TEMP chart as a starting point. Then see what you get on the range. I'm not recommending a particular powder here. Just trying to help ppl understand the importance of factoring in burn rate over temp. If you know that, I think it helps a lot at long range under large temp variations.

Folks—also keep in mind for many of these powders, linearity may be good until about 80-85F and then pressure/velocities may spike significantly beyond 85F.

 

[jdavistx]

Folks—also keep in mind for many of these powders, linearity may be good until about 80-85F and then pressure/velocities may spike significantly beyond 85F.

Good point. I agree. Always test under real conditions. Leave some ammo in the sun for a while and measure the temp. The table is just a starting point.

 

[Les Szabo]

I'm looking for powders to start load development on a short barreled .270 wsm with 140 berger classic hunters. (I don't know how short the barrel is gunna be yet, I plan to chronograph it at 26 inches and decide how much I am willing to lose from there). I can find some load data that should work for h1000 which will be a good starting place being as it shoots well from my 7 mag but H1000 is in short supply right now. I have lists of load data I just don't know adam from eve when it comes to powders. I am looking for temp stability first and velocity second. Im seeing re 26, aa magpro, ramshot, n560, 7828 ssc. Any ideas which powders I should be looking for?

Re 23 has been very good in the 270wsm

 

[jpope02]

RL23 & RL26.

 

[Flatbow]

I have seen that chart before but it does not have any of the newer enderon powders or the new RL powders that are supose to be more temp. Stable

 

[Flatbow]

RL 16 is much more stable than 17 and the others.
I may be a little fast for the WSM bjt works great in my CM.
Check Aliants web sight they have loads for the 16 for 270 wsm

 

[jdavistx]

I have seen that chart before but it does not have any of the newer enderon powders or the new RL powders that are supose to be more temp. Stable

True. Should be able to Google up the info for the powder or call the mfg.

 

[jdavistx]

I have seen that chart before but it does not have any of the newer enderon powders or the new RL powders that are supose to be more temp. Stable

FYI:
https://precisionrifleblog.com/2016/06/19/powder-temp-stability-hodgdon-extreme-vs-imr-enduron/

 

[Shootin4fun]

Never mind, looks like I have re 22

Good stuff, got very accurate loads but temp sensitive from my experience with it in 7 Mag. Texas Fall/Winter load development to Texas summer yielded a difference in velocity requiring adjustment.