You can run Re-26, it's a fine powder for this cartridge especially when working with the heavier bullets, Sierra 95 gr. MK in a 1:6.5" twist 30" barrel. I'm running Re-25 because I have more of it than the Re-26 right now, and for long range steel on the desert, it works just fine. The temps I shoot in are very stable this time of the year but I will run a different powder for summer or look for a milder climate to shoot in when my temps go up.