|This article, BR55S Battle Rifle, was written by Agreon. Please do not edit this fiction without the writer's permission.|
|This article, BR55S Battle Rifle, is currently under active construction.|
- "Quiet, and it outdoes the M7 or M6 any day. So tell me; What else could an ONI operator want?"
- ―Anonymous ONI operator
The BR55S was a rifle of no specific class. It was a shortened BR55HB SR Battle Rifle. It preformed most efficiently in three round burst. The weapon had a smartlink scope as well. It was similar in size, and appearance, to the MA5K Carbine. It was built for the purpose of stealth, as it had non removable external suppressor.
Misriah Armory was requested by the UNSC to provide a carbine that ONI operators could use in place of the M7S for operations that were likely to turn into large firefights, but be more effective in general. They delivered with a different upper receiver. It had a smaller barrel and gas tube. The gas tube is hidden inside the furnishing, unlike on the BR55HB SR. Also, it had a smart-linked scope hidden into it. The UNSC quickly gave ONI operators access, but also allowed Spartans to use it.
The weapon featured many important attachments that improved specific parts of it. The weapon's suppressor was shorter than the flashhider of the standard BR55HB SR Battle Rifle, and took its place, reducing length. Army troops have always had trouble with their HUD failing, and ONI operators rarely use any form of HUD, so Misriah Armory decided to create a folding x2 weapon-mounted red dot sight. The round counter on the weapon could be dimmed or turned off so that during operations in the dark, it was less likely to give an operator away. Also, the weapon boasted 9.5x40mm M634 Experimental High-Powered Semi-Armor-Piercing ammo, which could do large amounts of damage to non-flesh targets, such as electronic equipment or light vehicles. It also meant that if the trooper ran into a brute using power armor or the Reach-era chieftain armor, the brute could be easily killed, with little to no tradeoff with stealth.
The weapon was built for ONI operators, but Spartan IIs and IIIs saw its advantages quickly after. The Spartans recommended that it be issued to other Special Forces. The ODST then were given access to the weapon, but they almost never used it. When it got into the hands of the army troops and marines, the weapon began to show its strengths. There was no real use for it on the front lines that the MA5K couldn't fill, but the marines and army troops that did use it found it to be extremely effective. In urban operations where troops wouldn't want to give their position away to Jackal snipers, the stealth of the weapon became invaluable. If the trooper was facing off with an armored brute with a gravity hammer, the foe could easily be dispatched. Spartans used the weapon due to its size and stealth factor in relation to ballistic performance, which beat its only possible competitor, the 5x23mm M7S Caseless Submachine Gun. ONI used it for stealth, specifically. The marines and army troops liked its stealth and ammo. The weapon was loved for different reasons by different branches.