For any 6 XC shooters, wanting to try, Winchesters StaBall Powder with, the 108 Berger, Elite Hunter, Bullets,..
I started at 39.5 grains with both, Win and CCI primers and got up to 41.3 grains ( Close to Max for MY gun ).
Chrono'd 2,975 FPS out of, my 24" barrel and shot, sub 1/2", "Cloverleaf's" at, 40.7 grains (2,905 FPS ) and at, 41.3 grs, Jumping bullet .045, using, Norma cases. Hopefully, "Bugholes" coming from, my New Criterion Barrel as, I play with seating depths of, this bullet ! The EH is a Hybrid design, Bullet and "Jump's", nicely ! NOTE; My first try at .025 off lands didn't shoot well at, the higher charges !
I LOVE throwing charges of, Ball Powders ! Again, "work up", CAREFULLY ! I used 6 Creedmoor loading Data that's available on Hogdon's reloading site and backed off, about 3 grains from, suggested starting load then, worked up, in 1/2 grain increments til' obtaining desired Velocity and pressure on, the base of, case ( expansion was, .469 at the .200 dim). Had slight "cratering" of primers from my un-modified Factory, Rem 700 Bolt at, 41.3 grs.
The Primers were flat, but still rounded at edge ! PS; I still have, a 26" low rd count, 1-8 TW Criterion RemAge Varmint Taper, 6 XC, Barrel for Sale !