As more and more new cartridges are introduced, the various rationales for creating a wildcat, let alone an entire line of wildcats, have become less and less compelling. But go tell that to Bill Bruton and Michael McCourry, two guys who founded B&M Rifles & Cartridges based in South Carolina, in 2005. In fact, these guys now offer 12 proprietary rounds, the smallest of which is a 9.3mm (.366), with the largest being a .50 caliber. These guys belong to the Elmer Keith rather than the Roy Weatherby school of thought!
The whole thing began when Michael McCourry returned from Africa, where he had a dicey encounter with a hippo at extremely close range while using his 24-inch-barreled Model 70 chambered in .458 Lott. He felt it was enough cartridge, but in close quarters the rifle’s long length and 10-pound weight were just not responsive enough handling-wise for a dangerous game rifle.
The development of their first cartridge, the .50 B&M, was somewhat unconventional in that they started by first choosing the rifle that would be chambered for it, then designing the cartridge, rather than the other way around. Being partial to the Model 70 but wanting an action that was shorter and lighter than the magnum-length version on which his .458 Lott was based, Michael decided on the medium-length Model 70—the one designed around the WSM family of cartridges. This action is unique among so-called “short” actions in that it will digest cartridges loaded to an overall length of 3.1 inches rather than most short action limits of 2.75 and 2.88 inches.