I once had a rifle chambered in .264 Winchester Magnum. According to the ammo makers, this cal will go in excess of 3,000fps with 140 gr bullets. I don't know what the BC of these are but I do know that you can hand load them a little faster than factory specs. I also know that by the time you have worked up a load and sighted the rifle in, the barrel will probably be burnt out.
I bought mine years ago from someone that said it had less than a box of shells through it and it looked new. Wow, it shot a 36" group at 100 yards! I rebarreled the rifle to .300 win mag.
Shooting these slow powders to achieve super velocities with heavy bullets out of long barrels tends to be hard on the barrels.