Re: Rl-22 sensative
For what its worth to many combined answers to this thread: Hercules powders are double based, and yes I've found they are more temperature sensitive than most other powders. Both RL 22 and Rl 25 really seem to fit the burning rate spectrum of large cases really well and these powders seem to do their very best in cases when loaded right at the very max, thus their "allure" to many shooters, me included. I do believe Hercules powders vary greatly from lot to lot, by comparison to other brands.
Vitavouri powders are as uniform as any out there and most 6PPC shooters can tell you that for years vv133 was so uniform that they routinely noticed no difference at all from lot to lot and we're talking about shooters here that measure aggregate groups in the .000's.
The Hogdon Extreme powders are simply less sensitive to temperature and humidity changes and the short cut versions are simply more consistent in powder charges when being either thrown or measured.
So, to me Hercules RL's are like a drug addiction. I had a 6mm/284 that with RL22 gave me an honest 3,560 fps with excellent accuracy with the Sierra 105 gr. VLD- for about five hundred rounds; then the throat was gone!
Hope this helps,