A guy showed up at the range a couple of days ago with a new custom. I offered to chronograph it with my magnetospeed to help out as he forgot his tripod for his chrono. Rifle has a 22" proof barrel, velocity average was 2980 fps with Hornady factory ammo and 143 ELD-X. Accurate too. Know you KNOW what this new chambering will do. Expect a bit more velocity capability with a 24" barrel.