M392 DMR

"The single-shot DMR fits somewhere between the sniper rifle and the battle rifle. It's deadly at range, but a quick trigger finger and careful aim assure that even at medium to short distances it packs a punch."

- Game Informer

The M392 Designated Marksman Rifle, abbreviated DMR and formally known as the M392 Designated Marksman Rifle Serial Number: M45A771B, is a combat rifle used by the United Nations Space Command.

Background
Although it saw more widespread use throughout all branches of the UNSC prior to 2548, it has since been superseded in use by the BR55 in all branches but the UNSC Army, which is a land based fighting force.

Design Details
The M392 Designated Marksman Rifle is an air-cooled, gas-operated select-fire bullpup rifle that fires 7.62x51mm ammunition. It is mounted with a scope capable of 3x zoom and possess a fire selector switch, located above the grip of the weapon, and magazine release button, which is located directly above the magazine housing, located behind the trigger.

Trivia

 * Stamped on the comb of the rifle are the words ARMALITE MG UNSC. This is possibly the manufacturer or a reference to realworld manufacturer ArmaLite Corp.
 * On the Bungie Halo: Reach project page it clearly states that both the DMR and the MA37 shoot 7.62x51mm ammunition. This may point out that the DMR has a much higher stopping power because it is 3 headshots to kill.
 * A audio of the rifle being fired can be heard on Bungie.net.