BR55HB battle rifle

The BR55HB SR Battle Rifle is a United Nations Space Command infantry firearm, a variant of the BR55 Battle Rifle, and a service rifle of the UNSC Marine Corps.

Introduction
The BR55HB SR Battle Rifle is a gas-operated, magazine-fed, mid-to-long range weapon capable of 3-round burst or fully automatic fire. The modern successor to the BR55 Battle Rifle, the BR55HB SR remains relatively unchanged, firing the M634 9.5x40mm X-HP-SAP round from a 36-round magazine, and equipped with a 2x electronic scope for better accuracy at longer ranges. The BR55HB SR, however, is capable of automatic fire as well, and appears to have a slightly longer barrel than its antecedent. The penetrative power, accuracy, and range of the BR55HB SR is roughly equivalent to the BR55, although its accuracy is slightly decreased.

The BR55HB SR Battle Rifle appears to be one of the service rifles of the UNSC Marine Corps, and is standard-issue to many Marines as well as with the more-common MA5C Assault Rifle. While the BR55HB SR offers greater range and accuracy than the MA5C, the MA5C is easier to handle in close-quarters engagement. The characteristics of the BR55HB SR are comparable to the Covenant Carbine, although the mechanisms and aesthetics of the two weapons are highly different.

Advantages
The BR55HB SR Battle Rifle 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 out of range of other weapons. The BR55HB SR's accuracy and penetrative power make it a useful weapon to kill unshielded opponents: a single headshot with the 3-round burst instantly kills Grunts and Jackal Snipers and unshielded Jackals and Brutes at good distances. In multiplayer, it takes four headshots to kill a fully-shielded SPARTAN-II or Elite, and seven body shots. This has led to a well-known tactic colloquially known as the "Noob Combo" where a rifleman will use a Plasma Pistol to down the shields of an opponent and then fire a single headshot to kill the opponent, killing an enemy with only two shots. The BR55HB SR's accuracy and range also make it an option to suppress enemy snipers, as continual bursts disrupt the aiming of these enemy sharpshooters.

Disadvantages
At longer ranges, it is necessary to minimize strafing movements when firing to avoid "splintering" the shot grouping too much. Since each "shot" is really a three-round-burst, certain movements can break up your shot's grouping and greatly reduce accuracy. This also affects accuracy when firing from a moving vehicle such as a Warthog (especially when firing at a 90-degree angle from the vehicle's heading).

The Battle Rifle is not as effective at close ranges. Each bullet also acts as a tracer which gives away the shooter's position. Also, the range is limited compared to the Sniper Rifle. It also does negligible damage against vehicles, though can still cause warthogs and mongooses to spin out if the wheels are shot.

Physical Description and Appearance
The BR55HB SR is a bullpup, selective fire (Except in Gameplay), UNSC rifle that fires the 9.5x40mm X-HP-SAP round (see below). It fires from a 36 round magazine which fits flush in the receiver. The receiver is built directly into the underside of the butt of the gun and is located behind the grip (known as a bullpup configuration).

This titanium alloy weapon is gas-operated with a rotating bolt and therefore must be cocked 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. 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 mag 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 BR55HB SR, having a rifled barrel, has noticeable changes from the BR55. First off, it has a longer barrel for increased range and accuracy. It is fitted with a Trijicon ACOG-style scope on a modified carrying handle and now also has a trigger guard. The safety is also located above the handle of the weapon.

Changes From The BR55

 * Modified optical rail
 * New Trijicon ACOG-style scope
 * New trigger guard
 * Longer barrel
 * New reloading animation
 * Less magnetism
 * Slightly different firing sound
 * Slightly lower rate of fire

Besides these aesthetic/all weapons changes, the Halo 3 Battle Rifle is functionally identical to the Halo 2 version.

Ammunition
It is interesting to note the ammo used for the Battle Rifle. It uses a new 9.5mm x 40 Experimental Round. The 7.62 x 51 mm NATO round is a rather high-powered round used on the MA5B and on modern-day marksman rifles and machine guns. The 7.62 mm already has a history of having too much recoil because of the rounds high power, which made it hard to fire fully-automatically in assault rifles. While the BR55's larger 9.5 mm round would be heavier and would thus presumably generate even more recoil than the 7.62 mm NATO, this is not necessarily the case. Since the Battle Rifle's rounds have a noticeably shorter case length than the 7.62 mm NATO (40 mm vs. 51 mm), they most likely contain much less powder than the 7.62 mm NATO, which would yield less muzzle energy and thus less recoil, making the weapon more manageable.

The 40mm case may just be down sized to save space and house a more efficient powder yielding more power for the volume burnt, the increased bullet diameter maybe an engineering compromise to allow for a harder but less dense bullet material to achieve better terminal ballistics against armor; yielding the same or even more down range energy; anyone in 1 ton of powered body armor isn't going to notice much difference in the felt recoil of either of these high powered rounds.

However, the size of the ammo would have a problem fitting in the 36-round magazine of the current Battle Rifle. If a Heckler Koch G3 (which is chambered in 7.62mm x 51) has a standard magazine count of 20 and be the size that it is, it would be hard to see a cartridge much wider than the 7.62mm fit inside of a magazine of the Battle Rifle's size and with a capacity of 36 rounds. The Battle Rifle's magazine would have to be about twice as long as it actually is to hold that many rounds. This is a continuous pattern with UNSC assault rifles as a similar instance occurred with the MA5B. The MA5B has a magazine of 60 rounds chambered in the 7.62mm x 51 with a rather "small" magazine size, which looks to be smaller than the Battle Rifle's magazine.

How fortunate that in the 25th century that improvements in magazine technologies have allowed bulky springs and followers to be replaced, freeing up volume for more ammunition making magazines with more capacity than ever previously thought possible. A move away from the 7.62Nato's 12.01mm diameter bottle neck case design towards a straight wall case (nearer to 10mm) would also increase the number of rounds that could be held in a magazine. Viewing the casings from the rifle show that they are, in fact, bottleneck in design, like standard rifle rounds.

Influences
The BR55HB SR Battle Rifle's design is strongly based on its predecessor, the BR55 Battle Rifle. However, it appears to have been aesthetically inspired by the French FAMAS assault rifle and the U.S. Army's XM8 rifles.

Character Compatibility
This is the compatibility of the Battle Rifle in Halo 3.
 * Elites
 * Spartans
 * Marines
 * Brutes
 * Flood Combat Form (Human)
 * Flood Combat Form (Elite)
 * Flood Combat Form (Brute)

Trivia

 * Technically, "HB" could stand for "Heavy Barrel" which indicates the lengthened barrel of this variant. "SR" could stand for "Scoped Rifle", which is simply an additional description of this model.
 * In the Halo: Arms Race trailers and in Halo Wars, the BR55HB SR Battle Rifle seems to be automatic. But in Halo 3, however, it only fires in bursts of three rounds. This is most likely due to inaccuracies in the film, an automatic firing mode not used in the games due to balance, or a restricted feature only occasionally used in BR55 Battle rifles.
 * This weapon fires very similarly to the Heckler & Koch G36 and the Colt AR-15 which fires using the Short-Stroke Gas-Operated Rotating-Bolt, aside from the fact that most trigger assemblies for the G36 use a two shot burst.
 * The Marathon symbol is located on the guns left side, to the left of the ammunition counter display and roughly above the trigger guard.
 * WETA Studios made a replica Battle Rifle, Magnum, Sniper Rifle, Carbine, Gravity Hammer, Brute Grenade, and Rocket Launcher, to use in the (on hold) Halo film.

Related Articles

 * BR55 Battle Rifle