SRS99 series

The SRS99 Series, (collectively Sniper Rifle System 99), is a series of semi-automatic, gas-operated sniper rifles produced by Misriah Armory and used by the UNSC Defense Force. The rifle is standard for snipers and is configurable according to mission requirements.

Design details
The SRS99 series sniper rifle, by default configuration, is chambered for 14.5x114mm rounds. It is designed in the conventional layout: the magazine and operating system are located in front of the trigger. The magazine does not fit flush. Nearly all components of the weapon can be changed to fit the mission requirements, including the barrel assembly, (which includes the chamber), and the stock. That being said, everything can be changed to fit the current situation and satisfy the operator.

Firing mechanism
The SRS99 series sniper rifle is gas-operated. The action must be cycled to chamber the first round. Once the first round is fired, the gas from the previous round forces the bolt back, seating a new round on its return forward, and continues to do so until the mag is empty. Once the mag is empty and a new magazine is inserted, the bolt must be cycled, placing a new round into the chamber. The charging handle is on the left side of the rifle - allowing the user to cycle the action without unseating the weapon - and is physically a part of the bolt, and travels during operation of the weapon. The ejection port is on the right side of the weapon.

Ammunition
The SRS99 series sniper rifle, by default configuration, is chambered the 14.5x114mm APFSDS rounds semi-automatically from a standard four round magazine. These rounds are large in both length and width and are equipped with four symmetrical fins spaced equidistantly around the base of the projectile, stabilizing its trajectory to results of amazing accuracy, with a hit ratio of 97.3%. The terminal ballistics profile of the 14.5 x 114mm round is impressive; at 600 yards a round from the SRS99 series sniper rifle would go through about thirteen feet of flesh and bone.

The weapon can also be quickly and easily chambered to utilize other ammunition types, such as the 14.5x114mm HVAP rounds and the .450 rounds. The weapon can also fire specialized "grappling rounds" which are slid into the barrel, providing a means of securing ropes over long distances.

Development history
The SRS99 entered service with the UNSC Army in 2460. Due to its modularity and ongoing manufacturer support, the SRS99 was adopted by the other Defense Force branches in 2521. By 2557 at least three production series were in service: the original, the Series 2, and the Series 5.

Though introduced during the Insurrection, the SRS99's best known use was against Covenant forces during their war with humanity; it proved invaluable in eliminating most personnel types, (from Grunts to Hunters), from long-to-extreme range. It was later found to be generally effective against Promethean constructs during the first and second conflicts on Requiem in 2557 and 2558.

Known models

 * Sniper Rifle System 99 Anti-Matériel - The original model of the SRS99 series.
 * Sniper Rifle System 99C-Series 2 Anti-Matériel - A variant of SRS99 Series 2.
 * SRS99 99C-Series 2 Anti-Matériel B - A variant of the SRS99C-S2 AM.
 * Sniper Rifle System 99D-Series 2 Anti-Matériel - Another variant of the SRS99 Series 2.
 * Sniper Rifle System 99-Series 5 Anti-Matériel - The first version of the SRS99's fifth series.