Originally published in the November, 1995 issue of American Rifleman.

In every performance category, the .50 BMG easily outclasses any conventional rifle cartridge. With 12,000 to 14,000 ft.-lbs. of muzzle energy, the .50 BMG is more than twice as powerful as the .458 Win. Mag. and some 1 1⁄2 times as powerful as the .460 Wby. Mag.

Such power would allow a hunter to harvest any game animal on earth; and indeed, .50 cal. rifles have been used for hunting, primarily for extreme long-range shots. Lynn McMurdo, veteran hunter, .50 cal. shooter and custom bulletmaker, has taken game at more than a mile.

However, the scarcity of .50 cal. hunting bullets (McMurdo and Hornady are virtually the only sources) and legal restrictions in some areas limit the .50’s hunting use.

For most serious shooters, however, the appeal of the .50 BMG lies in its unsurpassed potential as an ultra long-range target cartridge. And what makes the .50 BMG so suitable can be summed up in two words: ballistic coefficient. Ballistic coefficient (BC) is a numerical representation of the aerodynamic efficiency of a projectile. For a given projectile velocity, the higher the ballistic coefficient, the less it will drop or be deflected by the wind. So what’s this got to do with .50 cal. shooting?

Well, according to the laws of physics, the larger the bullet diameter, the larger the potential BC. And indeed, the current crop of .50 cal. bullets has considerably higher BCs—some as high as 1.2—than any smaller-diameter bullets currently available.

Okay—but what difference does this make in real terms?

The accompanying table shows the long-range drop and wind deflection differences between a 220-gr. .30 cal. match bullet with a BC of .65 and an 800-gr. .50 cal. bullet with a BC of 1.0. The ballistic properties of high-BC bullets clearly make accurate estimations of drop and wind deflection—so important in long-range shooting—less critical.

Of course, the theoretical benefits of high BC values can be realized only if the projectile launching system—action, barrel, sights and cartridge components—are at a high level of development. Only in recent years have all the necessary elements reached such a level.

Early .50 cal. rifles were conversions of old antitank rifles or custom-made rifles built from scratch. Currently, however, there are about 20 different .50 cal. rifles available from about a dozen or so commercial manufacturers.

The majority are bolt-actions. Some are of a “conventional” design, simply resembling an enlarged two- or three-lug sporting rifle action. The Harris/McMillan M87 and M87R rifles, for example, both feature a cylindrical 2" diameter receiver and a full-diameter bolt with two forward lugs. A very similar action design is utilized on the two excellent rifles produced by McMillan Brothers (McBros) Rifle Co. (not the same as Harris/McMillan).

Many of Ron Freshour’s .50s, as well as the Rib Mountain Arms Model 92, also have a “conventional” look. American Arms and Ordnance markets a “conventional” action of about 2" diameter. The contact faces of the full-diameter bolt’s two forward lugs are angled at 45° rather than perpendicular to the bolt body, which is claimed to give greater action strength.

A number of bolt-action .50s are of shell-holder design. These use a recessed, flanged bolt face to retain the cartridge case by its extractor groove. Loading is accomplished by removing the bolt, inserting the cartridge head into the recessed bolt face, and reinserting the bolt and cartridge into the receiver. Unloading requires the same process.

Shell-holder designs were initially developed as the result of early military specifications for a .50 cal. rifle that mandated a length limit. They can be made shorter and lighter than a conventional bolt-action. Moreover, when maintaining a fixed length is a concern, a shorter action allows a longer barrel. Shell-holder actions are available from a number of manufacturers, such as State Arms Gun Co.; whole guns of this type include the Rib Mountain Arms Model 93, the Harris/McMillan M88, the Ultimate Accuracy Arms rifle (formerly the AMAC Model 5100) and rifles made by O.J. Buckheim and Northwest Arms Distributing.

Bullpups represent a trend among bolt-action .50s, offering a way to reduce gun weight and length without resorting to ballistically inefficient shorter barrels. While “standard” configuration .50s are typically more than 50" long and weigh 30 lbs. or more, bullpups can usually shave off 10" and five to 10 lbs.

Many bullpups are an “integrated” design, the receiver and stock forming one unit. The Barrett Model 90, the Ballard, the LAR Grizzly 50, and the Sugg are examples. While the first three use conventional shell-holder bolt actions, the Sugg is notable for having a titanium action employing a horizontally sliding breechblock as found in some artillery pieces.

There are currently two commercial semi-auto designs. The more famous of these—in fact, probably the best-known .50 rifle of any type—is the Barrett M82A1 Light Fifty. The brainchild of Tennessee gun designer Ronnie Barrett, the Barrett uses a cam-actuated rotating three-lug bolt in a short-recoil action. It is a relatively simple design that, like many current military and civilian arms, makes extensive use of heavy-gauge steel stampings.

The Barrett M82A1 rifle has found wide favor among governmental and military units here and abroad, thanks to its rugged design, easy takedown, and the high rate of fire provided by its semi-auto action and 10-round magazine.

A semi-auto .50 is also manufactured by Pauza Specialties. In contrast to the Barrett, the Pauza P-50 is machined completely from bar stock. It is a gas-operated rifle derived from the Soviet Simonov design of World War II and uses a five-round magazine. The Pauza is quite close to the Barrett dimensionally, with a 29" barrel and a weight of 30 lbs. Pauza also manufactures a carbine version of its .50 cal. semi-auto, with a 24" barrel and a weight of 25 lbs.

A prototype semi-auto .50 was introduced by McMillan Brothers (McBros) Rifle Co. at previous SHOT Shows. The gas-operated gun uses a vertical sliding wedge for lockup, weighs 32 lbs. and is 56" long. It uses the Barrett 10-round magazine.

Until fairly recently, anyone wishing to build a custom .50 would have been limited to surplus M2 machine gun barrels. Such barrels were fine for the rather modest accuracy requirements of full-auto fire, but lacked the match quality desired by serious long-range shooters.

Today, there are about a dozen custom barrelmakers catering to the .50 cal. crowd, including such well-known names as Krieger, H-S Precision, McGowen, Lilja, Lothar Walther and Obermeyer, as well as others that may be relatively new to many in the shooting community, such as Badger Barrels, Pac-Nor, K&P Gun Co. and Apex Rifle Co.