BR55 Heavy Barrel Service Rifle

The BR55HB SR Battle Rifle is an United Nations Space Command infantry firearm and a variant of the standard BR55 Battle Rifle.

Introduction
The BR55HB SR Battle Rifle is a variant of the Halo 2-era BR55 Battle Rifle introduced in Halo 3. It is a good all-around weapon and is virtually identical to its predecessor in terms of performance, even though it is much more difficult to aim, and doesn't possess Halo 2's "Automatic Headlock" feature. This weapon is available in Halo 3.

Summary
The BR55HB SR Battle Rifle is a gas-operated, magazine-fed, mid-to-long range weapon capable of semi, burst, or automatic fire. Due to difficult aiming caused by fully automatic fire, both variants have been restricted to three round bursts. It is relatively the same as the BR55 Battle Rifle but with some design changes. It still fires the M634 9.5x40mm X-HP-SAP round in three round bursts (or in fully automatic fashion as seen in Halo: Arms Race) from a 36 round magazine and it still has a scope with a 2x magnification. Its power, accuracy, and range are pretty much the same as the BR55. The main difference is that the BR55HB SR Battle Rifle has a slightly longer barrel.

Advantages
The BR55HB SR Battle Rifle, has reasonably high power, a decent rate of fire, and high accuracy with a 2x magnification scope; it can be used to deliver three-shot-bursts at medium ranges. In multiplayer, four full bursts to the head will kill a fully-shielded opponent, assuming standard shields. This weapon will kill an unshielded enemy in a single headshot. This requires that only one of the three rounds from a burst hit an enemy. Therefore, it is possible to kill up to three unshielded opponents in a single burst if they are grouped close enough to each other, though this is an uncommon occurrence. Right after you shoot however, it is possible to only shoot one shot rather than 3 bullets with a melee attack to disrupt the burst.

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.

Physical Description and Appearance
The BR55HB SR is a bullpup, fully automatic (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

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 efficent powder yielding more power for the volume burnt, the increased bullet diameter maybe an engineering compromise to allow for a harder but less dence bullet material to acheive better terminal ballistics against armour; yeilding the same or even more down range energy; anyone in 1 ton of powered body armour 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 possable. A move away from the 7.62Nato's 12.01mm diameter bottle neck case design towards a staight wall case (nearer to 10mm) would also increase the number of rounds that could be held in a magazine.

Influences
The BR55HB SR's design is based on the same weapons as its predecessor. It appears to be largely based on the French standard issue FAMAS assault rifle, and also has features resembling the US Army's prototype XM8 rifles. See here for more information.

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 may hint at a more sustained fire and "SR" could stand for "Scoped Rifle" which may also mean better accuracy, despite the fact that the rifle is dead-on most of the time.
 * 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 down to innaccuracies in the film, or an automatic firing mode not used in Halo 3 due to balance.
 * 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.

Related Articles

 * BR55 Battle Rifle