With so many handgunners looking to increase the performance of their pistols, it’s only natural that there’s a fair amount of experimentation with new calibers. One of the ways that’s been done is by necking down cases to accept smaller diameter bullets. That was the origin of the 9x25 Dillon and the .357 SIG. And as larger cases were necked down, the .400 Cor-Bon was born.
The .400 Cor-Bon is not much more than a .45 ACP case necked down to take 10mm bullets. It operates at higher pressures than the .45 ACP but lower pressures than the 10mm Auto. That allows it to offer performance similar to the 10mm, but with less felt recoil. The .400 Cor-Bon also differs from the similar but larger .40 Super, which features a longer case, higher pressures, and significantly increased performance.
It also allows pistols chambered in .45 ACP to be easily converted to fire a cartridge with similar power to the 10mm. This includes pistols such as the Glock 21 and the Colt 1911 family. Colt 1911 pistols chambered in 10mm have often had problems with cracking as a result of the powerful recoil of full house 10mm loads. The .400 Cor-Bon eliminates those issues.
The .400 Cor-Bon offers impressive performance, pushing a 135-grain bullet to 1,500 feet per second and a 165-grain bullet to 1,300 feet per second, for 620-675 foot-pounds of muzzle energy. The downside to the cartridge is that there are no commercially available loads in heavier bullet weights such as 180-grain and 200-grain, which really provide the 10mm Auto some of its top performance, especially against wild game.
There are also nearly no sources of .400 Cor-Bon ammunition, with Cor-Bon and Underwood being the only two that really loaded the round. Factory ammunition from Cor-Bon is going to be expensive too, at $1.75 per round. That’s why most .400 Cor-Bon shooters decide to handload. While brass, bullets, and dies are still readily available, supplies seem to be dwindling as newer shooters increasingly forget that cartridges like the .400 Cor-Bon exist.
If you have a .400 Cor-Bon barrel already, it could provide a useful addition to or change of pace from your current .45 ACP pistol. But unless you’re able to build up a good supply of ammunition, your survival armory might be better served by a pistol in a more commonly available caliber.