BR55 battle rifle

The 9.5x40mm Service Rifle, BR55, more commonly referred to as the BR55 battle rifle or simply as the BR55 or BR, was a high-caliber, selective-fire battle rifle which saw use in the as a special-issue infantry rifle throughout much of the . Hastily developed as a countermeasure to a threat that would never truly emerge, the BR55 seemed doomed to failure until the arrival of the in human space saw UNSC forces pitted against foes equipped with regenerating , against which the UNSC's standard performed less than effectively. The unexpected success of the BR55 rifle would lead to the introduction of an improved version of the weapon, the , towards the end of humanity's cataclysmic war with the Covenant.
==Development & Service History==
The BR55 battle rifle began life as the XM55, an experimental assault rifle platform chambered in 7.62x51mm. The firearm was pitted against multiple other designs in a bid to replace the aging MA5 rifle, but would ultimately be cast aside in favor of the more resilient XMA5A2, a derivative of the tried and true MA5 design that would go on to become the MA5B ICWS. Still, the XM55's exceptional stability and recoil dampening were duly noted.
However, in 2516 Insurrectionist rebels on the colony of created a chemical cocktail out of a variety of illegal street drugs, stolen hospital drugs, and various over-the-counter medicines. Nicknamed , the chemical was a form of synthetic adrenaline laced with a fast-acting coagulant. Humans injected with the substance entered a berserker-like state of intense rage, and became extremely resistant to pain and injury, as well as incredibly strong. Nearly one hundred insurgent soldiers would inject themselves with these rumbledrugs and charge blindly at UNSC patrols on the streets of the planetary capital. This was terrifyingly effective, with the rebel soldiers achieving an average kill rate of nearly three-to-one, as they were able to withstand countless hits from an MA5 rifle or .
Fearful that rebels throughout the would begin to create their own rumbledrugs to use in a similar manner, the UNSC put Misriah Armory to work developing a specialized cartridge that possessed tremendous firepower in order to allow UNSC soldiers to incapacitate rumbledrug users before they could inflict much damage.
The result was the M634 Experimental High-Powered Semi-Armor-Piercing round, a 9.5x40mm cartridge capable of inflicting devastating bodily harm upon even moderately armored infantry. However, the cartridge generated extremely high amounts of recoil when fired, limiting accuracy severely. In order to account for this, Misriah repurposed the XM55 design to fire this new cartridge. The result was the , a high-powered battle rifle with prodigious muzzle energy and accuracy far beyond that of the MA5 or MA5B.
Unfortunately, in 2520, just as the development process was wrapping up, the UNSC abruptly withdrew their funding. The UNSC's fears of rumbledrugs seeing widespread use by rebel forces had proven unsubstantiated, and rebels had not been recorded to have been using them at any point following the incident on Green Hills. Furious and unwilling to allow their money and effort to go to waste after four years of development, Misriah officials insisted that the UNSC continue funding the project. Reluctantly, the UNSC eventually agreed.
By 2522, the first XBR55 rifles were arriving in the hands of UNSC forces in the Outer Colonies. Reception of the weapon was mixed; although its performance was undeniably exceptional, it did not particularly excel in any area which the MA5 or M392 DMR did not already perform well in. It lacked the rate of fire and durability of the MA5 and its accuracy and range were both somewhat inferior to that of the M392 DMR. The only area in which it outclassed both weapons was in stopping power, and the 7.62x51mm cartridge used by both the MA5 and M392 possessed stopping power that was already plenty sufficient. Additionally, the weapon was highly intolerant of the rough conditions found on many Outer Colonies, and required constant maintenance in order to remain functional.
But in 2525, the alien empire known as the Covenant attacked the colony of . Many of the Covenant's infantry, particularly the so-called , were far more durable than human soldiers. It was against troops like these that the XBR55 truly shined, able to take down such resilient troops quickly and reliably from a safe distance. And once the energy-shielded started to become a common sight by 2526, it was clear that the XBR55 would be an invaluable asset to UNSC infantrymen in the budding conflict between humanity and this terrifying alien foe.
By 2528, Misriah had tweaked and finalized the design of the rifle (most notably reducing its magazine capacity from sixty rounds to thirty-six rounds for weight and balance reasons), and the UNSC officially adopted the weapon into their arsenal, naming it the 9.5x40mm Service Rifle, BR55.
Although rebel forces would again use rumbledrugs on the colonies of and in a desperate attempt to defend themselves against , had the Covenant never attacked this would've been far too little far too late for the UNSC to justify adding the BR55 permanently into its arsenal. The fact that it ever was adopted by the UNSC is mostly the result of pure coincindence. While the MA5 remained the backbone of the UNSC arsenal throughout the BR55's service life, the BR55 was nevertheless an extremely common sight on the battlefields of the Human-Covenant War, particularly in the . In 2548, a heavy-barrel marksman variant entered service in the UNSC, replacing the M392 DMR as the primary squad-level marksman weapon for all branches of the UNSC (with the exception of the ) for the remainder of the war. An updated model of the BR55, the BR85, began introduction in small numbers during the final months of 2552, and the BR55 would finally be phased out of service entirely in favor of this newer model by 2555, after roughly two decades of service.
==Design Details==
Designed to put extreme stopping power in the hands of the average infantryman, the BR55 was a gas-operated, general-purpose infantry rifle chambered in 9.5x40mm. By twenty-sixth century standards, this unusually large caliber qualified the BR55 as a battle rifle, a classification of firearm not commonly used as a standard-issue, workhorse infantry weapon since the mid-twentieth century.
However, prior to the Covenant invasion of Harvest, the 9.5x40mm cartridge was considered overkill, as it provided far more stopping power than a normal soldier could expect to need. To make matters worse, the recoil of the 9.5x40mm cartridge, while somewhat negated by the recoil-dampening design of the weapon, was still much greater than that of the MA5, and while in its three-round-burst mode the BR55 boasted a greater cyclic rate of fire than the MA5, switching the weapon to automatic would engage a rate reducer that drastically reduced the weapon's rate of fire, meaning that the weapon was unable to put rounds downrange as quickly as the MA5 in either firing mode. In addition, the BR55 was notoriously intolerant of the muddy or dusty conditions that were common on many Outer Colony worlds, further limiting its appeal in the eyes of UNSC forces deployed against Insurrectionist insurgents.
But the BR55 would prove itself as an invaluable component in the UNSC's arsenal when the Covenant attacked. Unlike the MA5, the BR55's higher energy rounds were capable of quickly and effectively breaking Covenant energy shields, and its greater effective range allowed UNSC Marines to pick off Covenant infantry from afar, where they could more easily react to incoming Covenant plasma fire.
The BR55's final production model would be optimized for three-round-burst firing, and many UNSC troops favored this fire mode, believing that it provided the best balance in terms of firing rate and recoil control. While the BR55 and its successors were all select-fire weapons boasting automatic, semi-automatic, and burst fire modes, it was the burst mode that would become closely associated with the BR55 design. When it was used in the automatic setting, however, a rate reducer would engage when the weapon was set to fully automatic, in order to make the recoil easier to control when firing the weapon in this mode. In spite of this, burst firing would remain the most heavily favored fire mode.
Like most UNSC weapons, the BR55 featured a standard electronics suite, located in the handguard, with controls and a display in the rear of the carrying handle. The suite featured a basic ammunition counter, and a specialized wireless uplink for uploading a reticle into a soldier's optical gear or directly into their field of vision via their neural interface. For soldiers lacking such sophisticated tools, a pair of traditional flip-up were also integrated into the weapon's carrying handle.
The BR55 also included standardized attachment rails on top of the carrying handle and on either side of the gas block. A rail-mounted Newsouth Optics LWBO-26 2-6x magnification was typically issued standard with the BR55, however, virtually any form of rail-mounted optics could be attached to the weapon, from simple red-dot sights to , extreme-range sniper scopes like the (although it was generally inadvisable to mount such an advanced, unwieldy optics suite on a weapon like the BR55). More specialized BR55 kits also sometimes included alternate muzzle devices for mounting .
===Ammunition===
Developed by Misriah Armory alongside the BR55, the most notable trait of the 9.5x40mm cartridge was its extremely high chamber pressure, meant to enable comparable velocity to the UNSC's standard issue 7.62x51mm cartridge in spite of the latter having a substantially greater case volume. Maintaining a short case length was important to the designers of the BR55 as it was critical for achieving the lightning-fast cyclic rate that enabled the weapon's burst function to be so effective, as the shorter case length meant a shorter distance over which the bolt would have to travel when the action cycled. However, this also resulted in a standard operating chamber pressure in excess of 700 megapascals, well above typical proof pressures for most calibers, let alone operating pressures. Such high chamber pressure necessitated special considerations in the composition and profile of the weapon's barrel, in order to ensure that barrel life was within the UNSC's requisite design specification.
The standard issue cartridge used in conjunction with the BR55 was the cartridge. The M634 X-HP-SAP consisted of a 242-grain (15.68 grams) copper-jacketed, lead-free, boat-tailed, spitzer-type projectile with a titanium-steel alloy core, seated in a Boxer-primed brass case filled with 40 grains of X34 propellant. The X34 propellant was a key element in the cartridge's design, being an experimental and highly energetic propellant compound that also burned somewhat cooler than average. The exact composition of the X34 propellant was a closely-guarded secret, known only to specific UNSC and Misriah personnel.
Like the M118 Full Metal Jacket Armor-Piercing cartridge, the M634 X-HP-SAP round was altered by Misriah in 2554 to feature a cupronickel jacket. In all other aspects, however, the cartridge remained identical to its previous version.
===Advantages===
===Disadvantages===
==Variants==
===BR55 Heavy Barrel Service Rifle===
:Main article: 
By 2545, the BR55 design had thoroughly proven itself in battle. Using data collected on the weapon's performance over the past decade, Misriah honed the BR55's mechanics to a razor's edge, developing a modification of the BR55 with range and accuracy superior to that of the M392 DMR. Known as the BR55 Heavy-Barrel or BR55HB, this new version of the weapon was significantly larger and heavier, featuring a longer, heavier-profile barrel, intended to improve accuracy and help maintain greater consistency during sustained fire. The gas port was moved further down the barrel as well, in order to decrease dwell time and soften felt recoil as well as to reduce pressure and wear on the port itself.
Prototypes for the weapon were in the hands of UNSC marksmen by the later months of 2546, and the weapon was well received. All branches of the UNSC would phase out the M392 DMR in favor of the BR55HB in 2548, with the exception of the Army, who believed that the increase in accuracy and range did not make up for the considerable increase in weight and size over the M392, nor for the BR55HB's noticeably higher malfunction rate.
During the later days of the Battle for in 2552, a shortage of functional MA5 or standard BR55 rifles and a surplus of BR55HB rifles would lead to the latter weapon seeing its way into the hands of normal UNSC troops as an improvised all-purpose weapon, despite its intended purpose as a marksman rifle. The BR55HB performed surprisingly well for this purpose, and the heavy-barrel variant of the BR55's successor, the BR85, would be an all-purpose weapon rather than a dedicated marksman weapon.
===S-55 Precision Rifle===
The S-55 Precision Rifle was a modification of the BR55HB intended for the civilian market. Featuring a semi-automatic only trigger group with a two-position selector switch in order to make the weapon conform with civilian firearm laws, the S-55 was fine-tuned for competition target shooting, although it was still relatively popular for personal and home defense purposes.
Notably, retired UNSC Marine Corps Sergeant Major Ingrid H. Schultz won the 2555 Intercolonial Shooting Tournament using a customized S-55 rifle.
==Gallery==
MCwithBR.png| reportedly made use of the BR55 numerous times during the opening days of the and in the on .
SF BR55.png|An wielding a specially-configured BR55 rifle, equipped with a suppressor and an underbarrel flashlight.
==UNSC Remarks==
==Notes==
Category:Demons of Hope
Category:UNSC Weapons
Category:BR55 series