In 1919, John Moses Browning developed a heavy machine gun, which the U.S. Army adopted in 1924. Eventually designated the M2, it is very likely the most successful military weapon ever used by any armed force. Still very much in service, it has been placed on aircraft, tanks, and jeeps, and in a quadruple anti-aircraft mount. She is a heavy gal, weighing 84 pounds without any accessories, and is usually mounted on a 44-pound tripod or bolted to something that won't move. Ma Deuce fires 500 rounds per minute. What makes her so effective is not so much her absolute reliability but the cartridge for which she is chambered. The .50 BMG round is a giant version of the .30/06, sending a 750-grain bullet out of the muzzle at 2750 feet per second. For many years, a small group of riflemen have been building rifles that chamber this monster.

Twenty firms, plus smaller shops, make .50 BMG rifles at present, so there's no shortage of guns to choose from. All .50s come in either bolt-action or autoloading configurations. Of the bolt actions, a few are magazine-fed repeaters, but most are single-shots, and of these, some are conventional bolts with solid receivers, while others are of the shell-holder variety. Here, you remove the bolt from the rifle, fit a cartridge into the bolt face, reinsert cartridge and bolt, turn the bolt handle down, and let 'er buck. Many shell-holder guns are made in bullpup style, where the action lies next to your face. This saves considerable length, which is important when you're dealing with barrels that go 30 inches and over.

Weights range from 20 pounds for hunting rifles to over 100 pounds for unlimited-class competition rifles. Yenason and Henry hunt with an LAR Grizzly, which is a 30-pound shell-holder bullpup. How does one carry a 30-pound rifle? Wendy simply lays it across her pack frame and starts walking.

No .50 BMG sporting rifle that I know of has iron sights, and every one has a muzzle brake, of which there are many weird and wonderful designs, backed by numerous claims. I know only this: A .50 BMG with no muzzle brake would be unshootable. What was left of you would go directly to the orthopedic surgeon.

Only two types of scopes can take the punishment of a .50: the Leu¿¿pold Mark 4 series and the Nightforce brand. These are tactical scopes in variable power, and most shooters like 30X or more at the top end.

The price for a .50 BMG can range from $2,000 at entry level to double that. When you add on the required $1,000-plus scope, you are talking a fair amount of money.

According to John and Wendy, .50-caliber shooters were without form and shape until about 20 years ago, when a group of the most serious banded together to form the Fifty Caliber Shooters Association (fcsa.org). The goals of the FCSA were to recruit new shooters and help them become proficient, and to provide official benchrest competitions where the breed could be improved.

Since then, the .50 BMG has been changed in ways that John M. Browning could not have dreamed. Ma Deuce, like all machine guns, is designed to spray bullets, not send them into the same hole. And so mili¿¿tary .50-caliber ammo is not made with accuracy in mind. The military stuff, in a good sporting rifle, with a good shooter, will give you 4-inch groups at 100 yards, which will enable you to hit exactly nothing at 1,000.

And so manufacturers started making better .50-caliber bullets, powders, primers, and brass. The knowledge of how to load the .50 BMG spread among the brethren, and pretty soon, it began doing amazing things.

John Yenason, who is among the top competitive .50 shooters, says that before showing up at a match you should be able to put five shots in a minute of angle at 1,000 yards-"a 10-inch group. If you can get five shots in 5 inches, or half a minute of angle, you will be regarded as a serious shooter. Squeeze things down to a third of