It's pretty good, or at least has been in the cartridges I've tried it in. The first round I used it extensively in was the .257 Weatherby Magnum, pretty similar to the .264. The load I worked up with 100-grain TSX's lost 27 fps from 70 to zero Fahrenheit, with no change in POI or accuracy.
“Montana seems to me to be what a small boy would think Texas is like from hearing Texans.” John Steinbeck
