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, more formally known as the Designated Marksman Rifle, Caliber 7.62 mm, M392, and commonly abbreviated as the DMR, is a select-fire rifle used by the United Nations Space Command.

Design Details
The M392 Designated Marksman Rifle is an air-cooled, magazine-fed, gas-operated select-fire bullpup rifle that fires 7.62x51mm ammunition.It is mysterious as to the fact of how the assault rifle and the M392 Designated Marksman Rifle use the exact same round (7.62x51mm ammunition) but in the game Halo Reach the DMR requires 4 shots to take down the shield of fully shielded spartan or sangheili (and one headshot to kill or 3 more body shots) but the AR requires 13 to take down the shield and 5 more rounds to kill. It takes a fifteen round detachable box magazine, similar aesthetically to the BR55. The weapon has a mounted optic capable of 3x magnification, and it possesses a fire selector switch located above the grip of the weapon. The M392 also has a magazine release button which is located directly above the magazine well, behind the trigger. The weapon has two ejection ports, one on the left and right hand sides of the weapon respectively, so that a left or right-handed shooter can fire the weapon.

Operation
The M392 DMR's intended battlefield application is similar to that of the BR55 battle rifle, fulfilling a role as the most effective medium-to-long range weapon in the UNSC arsenal. It is intended for experienced operators with proficient skill in shot placement and "controlled firing" since the recoil from multiple shots must be controlled to effectively deliver maximum damage to the target and to ensure that the target is neutralized at the fastest possible rate. Due to the introduction of an expanding reticule, the DMR requires a considerably higher proficiency in controlled firing and precision than the BR55 to attain successive head shots.

In order to deliver head shots to a target at medium-to-long ranges, a pause after each shot with the DMR is required to allow the reticule to contract to its smallest possible size. Immediately firing upon reacquisition of target maintains the maximum rate of accurate fire. While at close-to-medium range, it is only necessary to allow the reticule to shrink enough that it is roughly equal to the size of the target before firing again. At extremely close ranges, it is unnecessary to allow the reticule to contract at all, and it is most effective to fire the rifle as fast as possible.

Developmental history
Although it saw more widespread use throughout all branches of the UNSC prior to 2548, it had since been superseded in use by the BR55 Battle Rifle in all military branches of the UNSCDF but the Army.

Trivia

 * This weapon's semi-automatic functionality is similar to the battle rifle as seen in the 2003 Halo 2 E3 Demo.
 * The DMR was first featured in The Art of Halo 3 as a concept design for the Halo 3 Battle Rifle.
 * The designation of this weapon as a "designated marksman rifle" indicates that it was designed for use in squad-based combat, and not as a dedicated sniping tool. In the U.S. military, designated marksmen provide long-range support to their platoon. This contrasts with snipers, who operate in small teams and receive more specialized marksmanship training.
 * It only takes five shots to take down a fully shielded Spartan in MJOLNIR armor, provided the last shot is to the head. A skillful marksman can eliminate a shielded enemy with ease. This makes the DMR one of the most versatile weapons in-game; it is much more powerful than its successor, the Battle Rifle. Compared to the M6G Magnum, the DMR has a slower firing rate in exchange for higher accuracy and larger magazine capacity, however it shares the same basic amount of damage.
 * The DMR actually has higher accuracy than the BR55.
 * Originally, the DMR had only 12 rounds per magazine. However, sometime after the Halo Reach beta, this was increased to 15 rounds per magazine. Likely so that it is possible to get 3 kills without the need to reload.
 * Subscribing to Bungie Pro will give the subscriber a DMR visual flair. These are icons displayed next to the user's gamertag in Reach, similar to the septagon in Halo 3.
 * Closer inspection of the weapon's fire-select switch shows that it is capable of automatic fire.
 * In the game, the DMR incorrectly ejects the casing of the 9.5x40mm round used by the BR55 series, instead of the 7.62x51mm round which it actually fires.
 * The DMR will kill a fully shielded spartan in 7 body shots, another seven reference.

List of appearances

 * Halo: Reach