After a lot of deliberation on the rumors of RL22 being one of the most temperature sensitive powders out there, I still decided to try it in my .300 Winchester Magnum. I wish I would have tried it a long, long time ago. Anyway, I worked up a load this summer/fall and got a load that shoots sub m.o.a. consistently and averaged 3,184 fps for 6 shots fired through the chronograph on a nice sunny day of about 75 degrees. Fast forward now to December. Saturday the high was 24 degrees here in town. I was up on the hill(another 1,000 vertical feet) at about 10:30 in the morning, so I am being conservative in saying the temp was around 20 degrees. Fired six more shots through the chronograph and came up with an average of 3,146 fps. Conclusion: For a 50-55 degree spread my gun dropped 38 fps in average velocity. After this little test, I am glad I viewed the temp. sensitivity issue more as marketing hype than fact. Hope this little bit of information is useful.