I just loaded some shells for my 300 rum with the guns favorite powder, rl-22 and the new powder is way hotter than the last lot that I used. I had some of my previous shells on hand and ran both through the chrono at the same session. Old load 90 gr rl 22 vel 3205 with NAB 180's single digit deviation. New powder lot, same charge and bullets, 3353 velocity with heavy extractor marks on the brass. WTF! I called Alliant and they said that new loads need to be worked up with every new batch of powder. I have been reloading for 35 years and have never seen such a thing.