Reloaders have been dealing with temperature "sensitive" powders since day 1. It is a fact of life for reloaders and shooters whether using so-called "Extreme" powders or not. These less-sensitive types may be a bit better, but there have always been powders that were less sensitive than others. I recollect an actual test done some 30 years ago, loading several powders and then firing them under controlled temperature conditions. The results were enlightening, to say the least. For example, one commercial "ball" powder lost over 300 fps average when temperature dropped from 80ºF to -20ºF. A certain extruded powder manufactured in Europe dropped only 40 fps average during the same test. 300+ fps is a fair change in velocity, 40 is a non-issue at hunting ranges. One of the ways to be sure you know what is going on is to fire a shot at a target in the cold temperature and see if the POI has changed significantly. If so, an adjustment might be in order. I can honestly say, I have never missed a game animal due to changes invoked by a powder's temperature sensitivity. Knowledge is power, and one should make themselves aware of what to expect in varying temperatures. JMHO, Eagleye.
