Originally Posted by Len Backus
Roy, I wonder if that much velocity and pressure difference changes barrel harmonics and therefor POI or even group size.
It did not in my 300 RUM. I worked up loads in Ohio during late summer when it was about 80-85 degrees and hunted in Wyoming and Colorado when it was in the 20s and 30s. Granted, I didn't shoot far (under 400 yards), but the bullets hit where I wanted them to.
Hodgdon Extreme gets the nod from the bulk of reloaders for temp concerns where highly suspect powders like Alliant lose their luster due to repeated experiences of temp sensitivity.
My solution is to work up loads during the time of year that will be on par with the climate I plan on hunting. Fortunately, I do this here in Ohio where it can get just as cold as it does when and where I hunt out west. So far, problem solved.
Reloder powders produce some of the most consistent and best groups I've ever had, not to mention best velocities. No way I'm not going to use them any longer like a lot of guys do when they ultimately narrow down all choices to Hodgdon.