The big .375 Holland & Holland Magnum is the original belted magnum cartridge, and probably the best known of the medium bore cartridges. The only real competition for the .375 H&H, in terms of either versatility or popularity, is the .338 Winchester Magnum. No other medium bore cartridge for big and dangerous game has such a sterling reputation worldwide.

This enormously useful and successful cartridge was introduced in 1912 by the prestigious London firm of Holland and Holland. In competent hands, and with the right bullet, it is capable of taking any game animal on earth, including thick-skinned dangerous game like elephants, Cape buffalo, and rhino.

It is the most popular medium bore cartridge in both India and Africa, where it is the minimum bore diameter allowed for dangerous game in some jurisdictions. Ammunition is manufactured and distributed worldwide, wherever big and dangerous game is hunted. It is reasonably available in North America, where it is loaded by all three of the big ammunition companies (Federal, Remington, and Winchester), although it may not be stocked in the sporting goods department of a small town hardware store, or a big city department store.

The only real drawback to the .375 H&H, aside from its outsize recoil, is that it is based on a case 2.85 inches long and has an overall cartridge length of 3.6". Unfortunately, this is too long to function in a standard length bolt action; it requires a special "magnum" length action. The rim diameter of this big rimless style case is .532", which became the standard for just about all subsequent belted magnum cases. Holland & Holland's big case pioneered the use of a belt to control headspace, which allowed a lot of body taper and a small 15 degree shoulder. These features were necessary for to accommodate the long stick British cordite powder then in use. They also make for a cartridge that feeds from the box magazine of repeating rifles very reliably, an important consideration for a cartridge to be used on dangerous game. True to its name, the .375 H&H uses .375" diameter bullets. The SAAMI maximum average pressure for the cartridge is 62,000 psi.

Single shot and double rifles were and are chambered for the .375 H&H Mag. But until the Winchester Model 70 appeared in 1937 with an extra long, magnum length action there were no American made bolt actions long enough to accommodate the .375 Mag. This meant that only the wealthiest American sportsmen could afford to have .375's custom built on imported Mauser magnum actions, for such actions were very expensive. This limited the popularity of the .375 in North America for many years.

Today, several major manufacturers chamber their bolt action rifles for the .375 H&H Mag. These include Browning, Remington, Ruger, Sako, Savage, Weatherby, and Winchester.

The .375 not only has the punch for heavy and dangerous game, it shoots flat enough to make it useful for large plains game. Factory loads launch the popular 270 grain spitzer bullet (SD .274), at a muzzle velocity (MV) of 2,690 fps and a muzzle energy (ME) of 4,337 ft. lbs. Remaining energy at 200 yards is 2,234 ft. lbs. This load has about the same trajectory as the 180 grain bullet in a .30-06.

The trajectory of the 270 grain factory load looks like this: +2.7" at 100 yards, +3" at 125 yards, +1.5" at 200 yards, -3" at 268 yards. Thus, with this load the .375 H&H Mag. has a 268 yard maximum point blank range.

There is a 235 grain spitzer bullet (SD .239) factory loaded in Europe and available to reloaders in North America, which can be driven to a MV of 2,930 fps by a maximum load of 84.0 grains of H380 powder (Speer figures).

The 300 grain RN soft point and solid bullets (SD .305), designed for thick-skinned dangerous game, are factory loaded at a MV of 2,530 fps with a ME of 4,265 ft. lbs. The solid (FMJ) bullets are intended primarily for shooting elephants.

The handloader can duplicate or exceed all of these loads. Probably the most popular all-around bullet is the 270 grain spitzer. According to the Speer Relaoding Manual Number 13 their boat-tail spitzer bullet (BC .429) can be driven to a MV of 2611 fps by 76.0 grains of H4350 powder, and 2731 fps by 80.0 graind of H4350. These Speer loads used Winchester brass and CCI primers, and were chronographed in a 24" rifle barrel.

Of course, the price for high velocity with such heavy bullets is recoil. A 9 pound .375 Mag. rifle firing a 270 grain bullet at 2,690 fps generates about 40 ft. lbs. of recoil energy. The .375 hits hard at both ends!