BR55HB SR Battle Rifle

The BR55HB SR Battle Rifle (commonly called the Battle Rifle) is a UNSC infantry firearm and is a newer version of the BR55 Battle Rifle.

Design details
The BR55HB SR is a select-fire rifle that has been in service for over 27 years. The UNSC employs the Battle Rifle as a medium-range marksman rifle; it fires new 9.5x40mm ammunition from a 36 round magazine, which fits flush in the receiver. The magazine housing is built directly into the underside of the stock of the rifle and is located behind the grip. This titanium alloy weapon is gas-operated with a rotating bolt and therefore must be charged before the first round can be fired. The charging handle used to chamber the round is located on the left side of the weapon and does not move during operation, but is pushed back during reloading. The rifle has a housed magazine in the stock. The ejection port is located on the right side of the weapon. The BR55HB SR, has noticeable changes from the BR55. It has a longer barrel for increased range and accuracy. It is also fitted with Trijicon ACOG-style optics on a modified handle and now also has a trigger guard. The safety is also located above the handle of the weapon.

It is never stated exactly what the maximum effective range of the BR55HB SR is. The MA5C Assault Rifle, which was described as most suited for short to medium range, as opposed to the Battle Rifle's mid to long, has a maximum effective range of 300 meters and the Covenant Carbine, which is similar in use with the Battle Rifle, has a maximum range of 600 meters. It is stated that the Battle rifle could reach up to 900 meters with deadly accuracy; however, that may have been due to the design of the prototype Battle Rifle, deployed in 2524, the field issued Battle Rifle may not have that type of range.

Ammunition
The BR55HB SR uses a 9.5x40mm M634 X-HP-SAP. Even when fired in three-round bursts, the round produces little recoil resulting in nearly no muzzle lift. The rifle's ammo is more effective against both shielded and unshielded Covenant infantry than the 7.62x51mm NATO used in the MA5C Assault Rifle, as the increased accuracy leads to an increased amount of headshot the marksman can place on a target, and the increased kinetic energy of the round leads to faster shield depletion and increased damage to unshielded enemies.

Advantages
The BR55HB SR has reasonably high power, a decent rate of fire, and high accuracy with its 2x magnification scope. Its range is its primary advantage, allowing the rifleman to engage at longer ranges by leading shots. The BR55HB SR has a slightly lower recoil than its BR55 predecessor and has less muzzle flash, although the rounds fired are still visible in the air; the rifle's updated design also boosts range and accuracy, increasing the effectiveness of the 9.5mm rounds it fires. The scope of the BR55HB SR allows a skilled marksman to easily take down an unshielded target from medium range, making the battle rifle the best alternative to the high powered sniper rifle system that the UNSC provides for its marksmen.

Disadvantages
Attempting to engage a target at longer ranges requires more rounds and less movement as the rounds become inaccurate over longer ranges, while in close quarters combat it is fairly surpassed by the Covenant Carbine in terms of killing the opponent quickly with a headshot. Furthermore, its magazine can be depleted rather quickly. The weapon requires a good amount of skill in order to use it. The user must have an understanding of how the weapon works, and what to do with it when a situation arises. Each bullet fired from the weapon can act as a tracer, and can give away the shooter's position, putting him at risk of return fire. While effective at long range against light or unshielded targets, the BR55HB's performance against shielded infantry at close range is extremely challenging; the BR55HB, while still very effective, is not the weapon of choice at close range because of its design, and the fact that it can be easily overpowered by the Shotgun and Energy Sword.

Influences
The most obvious inspiration for the shape and design of this rifle is the French-made FAMAS assault rifle. They are externally nearly identical in design, featuring a bullpup configuration (the magazine and receiver behind the trigger) and a skeletonized carry handle. However, the FAMAS is an assault rifle, firing a 5.56 x 45mm intermediate round, and the BR55HB SR is a battle rifle, firing a 9.5 x 40mm round (which would never be used in this kind of weapon; the round is used for elephant hunting).

Another key inspiration for the BR series was the German-manufactured G36 line, particularly in the area around the carry handle and rail system. In its handguard, it also bears influence from another German design, the XM8 which was derived from the G36 and was slated to become the new standard service rifle for the United States military prior to its cancellation.

Tactics
An important thing to note is that the BR55HB SR can be used to great effect at medium to long range. The trick with making the Battle Rifle effective at long range is minimizing the operator's side-to-side movement. Strafing while firing greatly decreases the efficiency of the rifle. Additionally, while firing at a moving target it is important to aim in front of the target, especially when the target is moving perpendicular to the aim of the rifleman.