Originally Posted by coyotezapper
I totaly disagree with your "HYPE" statement concerning the Extreme powder line. I have tested H322, H4831, Varget, H1000 and Retumbo in the extreme line plus many other powder brands and have found the extreme line to be the most stable in temperature variations. These test are done with loaded cartridges having been placed in a fridge and freezer overnight then compared with cartridges that were not side by side. The extreme line has always been the best performer in these tests with the VV N500 series a distant second.
I tried the ice chest thing as well and found that the tests are not valid. Brass heats up Way Too Fast. Need to test in ambient conditions to get valid results but if it makes you feel better then fine.
Try it and you will see. I have done the testing on my competition guns and while the velocity variations are not as large as WMR (yes WMR is old but I have a lot of it and it performs in the mid size magnum cases) or RL 22 for example it is still present.
Example is H4350 for my 6.5x284 ---- with 49.3 grains and a 142 SMK (sorted by actual bearing surface with the Buhay gauge to eliminate any variable) the difference is avg of 2895 at 45 and at 85 2965. At 1K that is ugly unless you compensate for it which I do. These loads have a spread of less than 15 fps at 45 and 10 fps at 85 which is acceptable. Have done this on my sporters to a lesser degree as the shorter ranges the difference is not enough to worry about.
Specifically what results are you getting?