Introduced in 1910, the 9.3x64 (9.3x64 Brenneke) is the first and largest of several excellent cartridges designed by Wilhelm Brenneke. All of Brenneke's cartridges are based on the 8x57 rim and base diameter, with powder capacity (and thus velocity) determined by length, shoulder, and neck. The 9.3x64mm, bullet diameter .366, is the most powerful of the several European 9.3mm cartridges. The 9.3mm is the European equivalent of our .375, but most of the 9.3s lag behind the .375 H&H in velocity and power. This is not true of the 9.3x64; with a 285-grain bullet at 2690 fps it is absolutely the ballistic equal of th3 .375 H&H and, with its unbelted case and 2.5197-inch case, if offers lighter and more compact ammo and can be housed in a standard-length action. Though not nearly as popular as the milder 9.3x62 Mauser, the 9.3x64 is rarely seen in the United States, but it's a fine cartridge, excellent for our biggest bears and adequate for Africa's largest game. —
Craig Boddington