The Barrett XM500 is a gas-operated

Gas-operated reloading

Gas-operation is a system of operation used to provide energy to operate autoloading firearms. In gas-operation, a portion of high pressure gas from the cartridge being fired is used to power a mechanism to extract the spent case and chamber a new cartridge. Energy from the gas is harnessed...

, semi-automatic

Semi-automatic rifle

A semi-automatic rifle is a type of rifle that fires a single bullet each time the trigger is pulled, automatically ejects the spent cartridge, chambers a fresh cartridge from its magazine, and is immediately ready to fire another shot...

 sniper rifle

Sniper rifle

In military and law enforcement terminology, a sniper rifle is a precision-rifle used to ensure more accurate placement of bullets at longer ranges than other small arms. A typical sniper rifle is built for optimal levels of accuracy, fitted with a telescopic sight and chambered for a military...

/anti-materiel rifle

Anti-materiel rifle

An anti-materiel rifle is a rifle that is designed for use against military equipment rather than against other combatants ....

 currently in development by the Barrett Firearms Company

Barrett Firearms Company

Barrett Firearms Manufacturing is an American manufacturer of firearms and ammunition. It was founded in 1982 by Ronnie Barrett for the single purpose of building semi-automatic rifles chambered for the powerful 12.7×99mm NATO ammunition, originally developed for and used in M2 Browning machine...

. It is fed by a 10-round detachable box magazine situated behind the trigger in bullpup

Bullpup

Bullpups are firearm configurations in which the action is located behind the trigger group and alongside the shooter's face, so there is no wasted space for the buttstock as in conventional designs. This permits a shorter firearm length for the same barrel length for improved maneuverability, and...

 configuration.

It is based on the Barrett M82/M107 .50-caliber sniper rifle. It is intended to be a lighter, more compact alternative to the M82. Since the XM500 has a stationary barrel (instead of the recoiling-barrel design of the M82), it will likely have somewhat better accuracy. As with its predecessor, it comes with a removable, adjustable bipod

Bipod

A bipod is a support device that is similar to a tripod or monopod, but with two legs. It provides significant stability along two axes of motion .-Firearms:...

 mounted under the barrel, and a top-mounted Picatinny rail

Picatinny rail

The Picatinny rail or MIL-STD-1913 rail or STANAG 2324 rail or a "Tactical Rail" is a bracket used on some firearms in order to provide a standardized mounting platform. A similar system is the Weaver rail mount.-Description:...

 for attachment of a scope

Telescopic sight

A telescopic sight, commonly called a scope, is a sighting device that is based on an optical refracting telescope. They are equipped with some form of graphic image pattern mounted in an optically appropriate position in their optical system to give an accurate aiming point...

and/or other accessory.