Re: Alternate powders for 6.5 Creedmoor
fireguyty,
From the trends in the powder business I would assume that the Pro series powders would be less temp sensitive. Maybe they wanted it on the market and weren't willing to wait or pay to have it hot/cold tested is why they don't say that. I'm thinking 8208 is about the same. Talk about a godsend. I was using AA2520 in my 6.5 Grendel, because it gets the best velocity. The rifle is accurate enough that the small changes made by powders and primer changes didn't affect it enough to switch powders. However it required working up loads for summer and winter. Because, even though summer loads might be a bit milder, you don't get enough pressure to 'cook off' all the powder fast enough (now plasma) before it hits the gas port. Meaning light loads with the bigger volume cases tend to have high pressures at the port even though they don't peak anywhere near what you could load to.
Enter IMR8208. So far this has done well from 90+ degrees in summer to just under freezing conditions. I'm hoping things work out so I can test it at sub-zero temps later on this winter. Long story short, I've been able to get 2800 fps from this with 123 gr. bullets, and NO pressure signs. It's the right speed and has enough retardant with it, so as not to go over pressure at the gas port with a lower load charge.
Anyhow, back to bolt actions and the 6.5 Creedmoor. I would think that in certain bullet weights RE-17 would be excellent. It burns a little slower than H4350 but because it's a double base you usually end up topped out at where H4350 begins. So, if pushing lighter bullets it's a viable alternative. And it is very temp tolerant from what I've found. If you're having issues with H4350, and need to stick with an Extreme powder, then try the H4831SC. Again, single base, but slow and will work well with the heaviest bullets in that caliber without running out of room or hitting the pressure ceiling.
-good luck