|This article, BR55 Designated Marksman Rifle, was written by RelentlessRecusant. Please do not edit this fiction without the writer's permission.|
The BR55 Designated Marksman Rifle (BR55 DMR) is a variant of the BR55HB SR Battle Rifle in limited usage by the UNSC Marine Corps and the UNSC Special Operations Command, manufactured under special contract by HRV Armament Company.
The BR55 DMR is an accurized variant of the BR55HB SR Battle Rifle intended for a designated marksman, and is not a dedicated sniper rifle system intended for a specialized sniper. It is an adapted variant of the BR55HB SR Battle Rifle, with a small number of modifications to transform its role into a longer-ranged weapon capable of giving support fire to infantry formations of the squad or platoon level, although it lacks the penetrative power and range of dedicated sniper rifle systems such as the S2 AM or AS DAM series. However, it is more suitable for regular field operations than more specialized sniper rifles, with a lighter weight and a more shapely bulk to allow for more practical field maneuvers and longer endurance.
Although the BR55 DMR was initially intended for more widespread distribution during the later years of the Human-Covenant War amongst frontline Marine units, it incorporates a number of more specialized modifications that have increased its cost and have instead made it more appealing to UNSCSOCOM operators.
- Barrel: The BR55 DMR incorporates a full-bore barrel with no tapering along the length, lessening recoil compared to the BR55HB SR's partially-tailored heavy barrel and also a longer barrel to allow for dissipation of the projectile's kinetic energy, allowing for engagement over longer ranges. These increases in barrel cross-section and length lead to a noticeable increase in weight and also make the rifle unsuitable for close quarters combat (CQC), where light weight and easy handling are integral. Importantly, the BR55 DMR has a threaded barrel that acts a receiver for any number of standard attachable flash-sound suppressors, making the DMR choice for special operators, significantly reducing ballistic crack and muzzle flash despite the BR55 DMR projectile's high velocity. This is an attractive option for covert nighttime operations, where the suppression of muzzle flash greatly enhances surreptitiousness in the field. An infrared laser sight is also mountable on the side of the barrel.
- Butt Stock: The BR55 DMR moves away from the traditional BR-series metal stock, instead utilizing a more lightweight glazed fiberglass. The stock is textured, allowing for more comfortable cradling, and also a high comb that stabilizes the operator's cheek and allows for stable, steady sighting through the telescopic sight. A side-mounted chinpiece is also available. The stock is painted with a night-black finish, accommodating nighttime usage, although other camouflage schemes are readily applicable. Although there was consideration to make the DMR's stock a folding or detachable stock, this was eventually vetoed; the materials used to make such stocks are more pliable, and the DMR's intended special operations forces (SOF) usage in extreme environments discouraged this.
- Action: The underside receiver sports a magazine release and a selective fire trigger group with "S/1/3" selective fires; safed, semiautomatic, and three-round burst; being not a true dedicated sniper rifle, and being used in a potentially target-rich hostile environment, it is equipped with a semiautomatic action instead of a bolt-action. The BR55 DMR's three-round burst is meant for general Marine purposes against armored or shielded targets, such as armored Sangheili or Jiralhanae, which are resistant to limited semiautomatic fire.
- Upper Receiver: The BR55 DMR also has a modular upper receiver capable of accommodating a mid-range ACOG scope or a long-range telescopic scope, or rarely, a red aiming reference. The two former scopes are capable of infrared or NVG enhancement. Certain UNSC Office of Naval Intelligence operators are said to have electronic enhancements to their scopes that allow for live "gun camera" recording and high-definition image reconnaissance (IMINT). Rare and advanced "image analysis" equipment is also reported that may potentially allow for very rudimentary analysis of targets for special forces applications.
The BR55 DMR was first seen in usage by Gauntlet Company and the ODST operators of the 2nd Orbital Special Warfare Battalion as a "high-powered sniper rifle" in December 2559. It was later used by Chief Petty Officer Kimberly Ivy Blackburn in December 2564 in Operation: PAIR RULE on Tau Capricorni B, Tau Capricorni System.