The .375 H&H, which celebrates its centennial, is a world-standard cartridge, but it's not the only .375. Not counting wildcats and proprietary cartridges, we have: .376 Steyr, .375 Flanged, .375 H&H, .375 Ruger, .375 Weatherby Magnum, .375 Remington Ultra Magnum and .378 Weatherby Magnum.
Performance is superb across the board, but there are differences in ranging capabilities, energy yield, recoil and action size the various .375 cartridges can be housed in. If you're looking to get a .375 you need to decide what meets your requirements—and the recoil you are willing to absorb to answer that need. I separate the current crop of .375 cartridges into slow, medium, and fast categories.
Apart from the deer/black bear-capable .375 Winchester, which I'm not going to discuss here, the slow .375s include the .376 Steyr and .375 Flanged.
In the past I have given short shrift to the .376 Steyr. It is a capable cartridge that propels a 270-grain bullet at 2,560 fps, but I saw no need for its existence. Designed by Hornady and Steyr as an ultimate extension of Jeff Cooper's "scout rifle" concept, the .376 Steyr is not popular and probably won't be, but I was wrong about it.
Its ballistics are hardly anemic, yet it's a mild-mannered cartridge that can be housed in .30-06-length actions. It is perhaps at its best for bear and moose at close to medium ranges, but since as a .375 it's street legal for African dangerous game, it makes an okay cartridge for buffalo (as long as you're careful), and it's great for lion and large plains game. Plus it has relatively low recoil, so pretty much anyone can handle it.
The .375 Flanged ("flanged" being the British word for "rimmed") was introduced along with the .375 H&H but as a slightly downloaded version for use in double rifles and single-shots. It's a standard offering from double-rifle makers, but ammo is available only from small, custom suppliers. Normally loaded with a 300-grain bullet at 2400 fps, the .375 Flanged is not the equal of the .375 H&H, but it's close enough.
There are just two: the .375 H&H and the fairly new .375 Ruger. Standard .375 H&H velocities are a 270-grain bullet at 2,690 fps, offering about the same trajectory curve as a 180-grain .30-06; and a 300-grain bullet at about 2,530 fps. With its nominal 2.8-inch case the .375 H&H requires a "full-length action.
Ammo is widely available, and it's a very shootable cartridge that most people can learn to handle. It remains one of the world's most versatile cartridges, with trajectory flat enough for most conditions and, when needed, enough power and penetration for the world's largest game.
When the Hornady and Ruger cooked up the .375 Ruger, their goal was to equal .375 H&H velocities but in a shorter, fatter, unbelted cartridge that would fit a .30-06-length action and a standard belted magnum bolt face. Rim and base diameter are the same as the .375 H&H's, but the case body maintains that diameter with very little taper. Thus, although the case is shorter at 21/2 inches, it has similar case capacity to the longer .375 H&H.
The .375 Ruger actually exceeds standard .375 H&H loadings by some margin, with a 270-grain bullet at 2,840 fps and a 300-grain bullet at 2,660 fps. This means that you can do at least anything with a .375 Ruger that you can do with a .375 H&H—and a bit more. Ammunition is currently loaded only by Hornady, so it's not nearly as available as .375 H&H. Recoil is pretty snappy. With similar gun weight it is obviously about the same as the .375 H&H, but take a pound off the rifle and you'll feel the difference.
There are three fast .375s from the major makers: .375 Weatherby Magnum; .375 Remington Ultra Mag; and .378 Weatherby Magnum.
The .375 Weatherby Magnum is simply the .375 H&H case blown out, increasing case capacity by removing the body taper, with the Weatherby shoulder added. As with all Weatherby cartridges, specifications for the .375 Weatherby call for "freebore" (a lengthened unrifled throat), which increases velocity. Ammo is loaded by Norma: a 300-grain bullet at 2,800 fps and 5,224 ft.-lbs.
The .375 Remington Ultra Mag is a necked-down .404 Jeffery with the same nominal case length as the .375 H&H and Weatherby but a larger case diameter of .550-inch, with the rim is rebated to .534-inch. Despite its girth, it can be housed in most actions that will accommodate a .375 H&H.
Pressures are conservative, and .375 RUM factory velocities show a 270-grain bullet at 2,900 fps and a 300-grain bullet at 2,760 fps.
Both the .375 Weatherby Magnum and .375 RUM deliver more than 5,000 foot-pounds of energy, and both shoot considerably flatter than any .375 H&H or .375 Ruger load. And, yes, you will feel it in the "equal and opposite" reaction of recoil. But you won't feel it as much as you will the .378 Weatherby Magnum, the fastest and most powerful of the bunch.
The .378 Weatherby Magnum case is essentially a belted version of the .416 Rigby case necked down to .375. With a rim of .580 inch, belt diameter of .604 inch, and case length of 2.913 inches, the .378 Weatherby Magnum requires a full-size magnum action.
Its ballistics are simply astounding: a 270-grain bullet at 3,180 fps and a 300-grain bullet at 2,925 fps. This gives it a trajectory curve like the .270 Winchester but with energy ranging from 5,700 to more than 6,000 ft.-lbs.
All the fast .375s offer great performance but suffer from single-source ammunition: Remington for the .375 RUM and Weatherby for the .375 and .378 Weatherby magnums.
The other consideration is that when you go up in velocity, both recoil velocity and recoil energy go up very quickly. The .375 Weatherby and .375 RUM hit you hard and fast, with considerably more felt recoil than a .375 H&H of similar weight. The .378 Weatherby Magnum is, in my view, one of the most brutal cartridges to shoot.
I tried the fast .375s and decided they were too much gun for me. Remember that any .375 is likely to be your only rifle on a hunt, or it might be the lighter of a two-rifle battery in Africa. Over the course of a safari, you might shoot it a lot. That's the problem. The rifle you carry throughout a safari but might actually shoot only once or twice (say, on the day of your buffalo and the day of your elephant) doesn't need to be fun to shoot. The rifle you shoot every day, however, had better be easy to shoot.
So these days I shoot either the .375 H&H or the .375 Ruger. The H&H has the obvious edge in availability, as well as tradition, but Ruger's M77 Hawkeye African is such a cool and inexpensive little package that it's almost irresistible.
But a lot of you are tougher than I am, and the faster .375s deliver unquestionable benefits—if you can shoot them well without getting jumpy. Thanks to its modern unbelted design the best of them is probably the .375 RUM, but it has not become popular.
The full text of this article, plus a ballistic comparison chart of all the cartridges discussed, appear in the March/April 2012 issue of RifleShooter magazine.