With the 264 WM, I will mention a couple of things. First, this cartridge EATS barrel throats, but H1000 burns cool and will greatly enhance the barrel life as will N160.
Second, if/when you try R#25, expect the best accuracy, and lowest SD(sub 10 fps) with a Winchester Magnum primer, while a fed 215 will just blow the groups up with this powder!
Years ago, I shot a Winchester Model 70 out with 129g HOrnady sp with IMR 4831 before I learned how well H1000 performed with 139g Lapua's in a Rem 700.
When you have no experience with the 264 Win Mag caliber, it can seem to be particularly finicky to find a load for. If you follow the Kiss, Find Pressure, Rock On method, your success will be easy. Barrel life was almost used up developing loads on my Model 70(my ignorance), not so much on the Remington. When I did find a load with the 123g Lapua and 129g Hornady Sp, velocity was 3175, and I never used more than one shot on a deer or hog...never, under 300 yards was typical. A Brux 8T in this caliber would be my choice because they are slick as glass inside!
