|This article, BR55-SS Battle Rifle, was written by Chiafriend12, but may be used freely by other users even without the author's explicit permission.|
The BR55-SS Battle Rifle is a BR55 Battle Rifle with a sound suppressing permanently fixed silencer on the end of the muzzle.
It was first unofficially introduced late in the Battle of Harvest. The exact year of when they were first used is unknown, but it was noted by a UNSC Lieutenant Colonel in a document in 2530 that "Marines have improvised during the fight here [on Harvest], and improved their BR55s by adding on crudely made silencers to the end of the muzzle. They work well, and I recommend that a custom variation to the BR55 be designed with an either permanent or removable silencer.".
Two years later, in 2532, the BR55-SS was introduced. It took two years to make an official variation and manufacture compatible silencers because it was considered of "low" priority at UNSC headquarters.
The BR55-SS model battle rifle continued service until 2556, when the UNSC was not at war, and had no reason for such a "trivial modification", as said by one of the head staff that deactivated the model. After its deactivation, Marines still sometimes made their own crude version of the SS.