BR58 Battle Rifle (troud38)

The BR58 Service Rifle is an evolution of Misriah Armory's famed BR55 series that saw much use during the Human-Covenant War, and ultimately the successor of the series. While not a total overhaul of the weapon system, the BR58 featured several improvements and combined several features of the earlier BR55 and BR55HB SR. Entering service in 2555, the rifle quickly became the standard issue service rifle of both the United Nations Space Command Marine Corps and Navy, replacing the earlier BR55 series and even the venerable MA5 series assault rifle.
== Operation and Design ==
As with it's predecessor (BR55 series) the BR58 is a short-stroke gas piston, rotating bolt bullpup rifle chambered in the hard hitting 9.5X40mm M634 High Powered Semi-Armor-Piercing cartridge. This cartridge was highly effective during the Human-Covenant War and quickly gained favor with the ground forces of the UNSC Armed Forces.
The United Nations Space Command Marine Corps was thoroughly impressed with the performance of the BR55 and it's variants during the war, but post-war looked to join with the other branches of the military to standardize and streamline the equipment issued to troops. This especially extended to simplifying the arsenal of infantry weapons in the field as there were several different variants of rifles, handguns, and submachine guns in use during the war. Two variants of the BR55, the standard rifle and the Heavy Barreled Service Rifle (BR55HB SR), both saw extensive use in the hands of Marines. While both variants were much loved by the men and women who carried them, the Marine Corps and Navy submitted a request to Misriah Armory for a successor series that consolidated the features of both rifles. A key feature that was desired to be kept was the heavy barrel, now to be the standard barrel profile. Another change the Navy and Marine Corps agreed to was the elimination of the four position selector (Safe-Semi-Burst-Full) to a simplified three position (Safe-Semi-Full). With the elimination of burst fire, Misriah lowered the rate of fire in fully automatic from 900 rounds per minute to 700 rounds per minute, creating a very comfortable and controllable weapon in fully automatic fire. Notably, magazine capacity was reduced from 36 to 32 rounds, as it was hoped that smaller magazines would lend to better storage and therefore the carrying of more ammunition. 
Further seeking to make the BR58 an improved design over it's predecessor, Misirah designed a new front hand guard that featured a proprietary rail mounting system that would be adopted by the entire UNSC Armed Forces as the M2555 Rail Mounting System. This rail was also featured on the rifle's trademark carrying handle, allowing for the mounting of several different sighting systems. The rifle was also capable of being fitted with an M301A grenade launcher or an XM330 Breaching Device with the underslung rail attachment. 
While Misriah hoped that there would be universal adaptation of the BR58 by all branches of the armed forces, ultimately only the Marine Corps and Navy would adopt the rifle, with the Air Force and Army choosing a different design in their own testing trials. Much to Misriah's disappointment, the Army refused to adopt the M634 cartridge as a whole, preferring to retain 7.62x51mm and begin development of a cartridge of their own design. 
== Service History ==
Prototypes of the new rifle entered testing in late 2553, with field testing with 3rd Battalion, 5th Marine Regiment beginning in 2554. Reports from the field were overwhelming positive, and the rifle was officially adopted in February 2555 as the new official service rifle of the UNSC Marine Corps and Navy, replacing the BR55 series and supplanting but never totally replacing the MA5 series of assault rifle, notably the also new MA5F Individual Combat Weapon System (troud38).
The weapon system saw it's first taste of combat in the hands of SPARTAN-077(troud38) and Havoc Team (troud38) against forces of a Jiralhanae-led Covenant Remnant.
Category:UNSC Weapons