The BR55 Battle Rifle is a United Nations Space Command infantry service rifle, first seen in Halo 2, although it has been in service since 2525. It is the older of the BR55 series rifles. It is most notable for its powerful three-round burst fire and accurate 2x scope, making it more efficient at farther ranges than the Assault Rifle.
About this creation
The BR55 Battle Rifle is a gas-operated, magazine-fed, mid-to-long range weapon capable of semi-automatic and burst-firing modes. Prototypes of the Battle Rifle were used in 2525 at Harvest, but it entered active service in 2524. The weapon is canonically capable of fully-automatic fire, but only the three-round burst mode is encountered in game. In Halo 2 the Battle Rifle fires the M634 9.5x40mm X-HP-SAP round from a 36-round magazine, though in Halo 3 the weapon utilizes the 9.5x40mm KURZ. Additionally, the weapon features a scope attachment capable of 2x magnification. It does reasonable damage to enemies, being able to kill most within a few bursts (normally four when enemy is fully shielded), and easily land headshots on unshielded targets, resulting in a one-hit kill. Its accuracy and range are also reasonably high, being able to hit a target from medium to semi-long ranges. It is highly recommended to always have one on hand on higher difficulty levels.
The BR55 features a bullpup design that fires a three round burst from a 36 round magazine UNSC rifle that fires the 9.5x40mm X-HP-SAP round. The magazine housing is built directly into the underside of the stock of the weapon and is located behind the grip.
This titanium alloy weapon is gas-operated with a rotating bolt. Therefore, the charging handle must be racked before the first round can be fired; this will put a round into the barrel. The charging handle used to chamber the round is located on the left side of the weapon and does not move during operation. Once the first round is fired, the gases from that round—and those to follow—impinge upon a gas piston, which pushes back the bolt carrier, rotating the bolt inside and continuing to chamber rounds until the magazine is empty. Once the magazine is empty, the charging handle (even though not illustrated in-game) can either be pulled back and locked or it can be fully cycled after a fresh magazine has been housed. If it is pulled back and locked, then it must be pushed forward once a fresh magazine is housed to chamber a new round. The magazine release button is located on both sides of the gun with an arrow pointing down towards the housed mag in the stock. The ejection port is located on the right side of the weapon. There is also a fire selector on both sides of the ammo display.
The BR55, having a rifled barrel, is 89.9cm long and is fitted with a scope for increased accuracy. The scope is mounted on the optics rail. The safety is also located above the handle of the weapon.