460 Weatherby. An older fellow (at the time - early 70"s) brought it into the shop and asked if we could sight it in for him. Said he was going to the Yukon for Brown Bear and wanted stopping power. At well over 7,000 ft.lb. muzzle energy, the power was there. Can't recall how he made out on the hunt though. We sighted it in using 500gr ammo. Don't think I could shoot that beast today, as my 300WM is a real shoulder bruiser.