Temp Sensitive Powder

[Standbanger]

RL 17 is regarded as temp sensitive. What reactions does the temperature have on this powder is it just when its a hundred degrees outside or when its twenty degrees outside ?

 

[brentc]

RL 17 is regarded as temp sensitive. What reactions does the temperature have on this powder is it just when its a hundred degrees outside or when its twenty degrees outside ?

Keep it below 85 degrees F and you won't see any issues.

 

[FearNoWind]

Keep it below 85 degrees F and you won't see any issues.

I pretty much concur with that. But because I can't always anticipate precise temperatures I'll face on the range (I've seen it vary as much as 25 degrees from late morning to early afternoon) I kept the charges fairly moderate when I used RL17.
I don't use it any longer, just for that reason. Never did like having to work up a winter and summer load.

 

[Standbanger]

thanks for the responses

 

[FEENIX]

I don't use it any longer, just for that reason. Never did like having to work up a winter and summer load.

That's why I developed a fall load for my .300 WSM. gun)

 

[tbrice23]

That's why I developed a fall load for my .300 WSM. gun)

LOL. Me too!

 

[dwm]

I used to shoot BLC-2 in my AR. In Texas at 8AM in the summer it may be 75 degrees. I could shoot <1/2 inch groups from 8AM to 9:30 AM. From 10 to 11:30 the temp would go to 90 to 95 degrees and the group size would open up to 3/4 to over an inch. Switched powders and the problem went away.

This was really frustrating...

There are so many good powders on the market, why put up with this?

Just saying ...

 

[Engineering101]

Turns out RL-17 (and its brothers RL-26/RL-33/RL-50) all made by Nitrochemie in Switzerland are considered to be moderately temperature sensitive. They are rated for 0.5 fps velocity change per degree F of temp change. That obviously assumes some standard load in some standard rifle and your mileage WILL vary. RL-23 on the other hand is supposed to be flat out temperature insensitive and this is made by Bofors in Sweeden. It is based on the same formula as AR-Comp which is likewise temperature "insensitive".

Bottom line, if you thought RL-17 was bad, you haven't seen bad. Powders like RL-22 or RL-25 really suck for temp stability. Those are the reasons Alliant came out with RL-23.

H1000 and Magnum are "insensitive" to temp changes and there are others that have come out recently like IMRs Enduron line.

Personally I don't have a problem with the temp sensitivity of the RL17/26/33/50 lineup as you do get some pretty good performance boosts from those powders. You just have to be aware of the powders limitations and not do something with them that they can't do.

 

[Okanogan]

RL-23 on the other hand is supposed to be flat out temperature insensitive and this is made by Bofors in Sweeden. It is based on the same formula as AR-Comp which is likewise temperature "insensitive".

My experience has been RL-23 exhibits some temperature sensitivity. With my 300WM, I've seen 190gr VLD shoot faster in the afternoon than 185 VLDs in the morning with all other load parameters equal in the same range session. I have also seen differences between range sessions with similar loads when the temps where significantly different (30F). My feedback is anecdotal but based off Magnetospeed V3 data. Your results may vary.

 

[AZShooter]

I have found RL-17 has some velocity change. Sure beats win 760 and some of the older RL powders like 22.

I use RL-17 in:

two 338 RCMs (225 accubond and 300 gr berger)
284 win (168 VLD)
6mm-284 (95 gr classic hunter)

I just looked up the 6mm-284's performance from 45 to 90 degrees. The loss/gain is more than .5 fps per degree, closer to .8 fps per degree for this particular cartridge:

45 degrees 3433 (12-15-2014)
80 degrees 3465 fps
90 degrees 3473 (8-21/15)