During the Sol War, the newly reborn United Earth sniper teams determined that they required a semi-to-full automatic, lightweight weapon, yet capable of doing long ranged combat that most sniper missions require. This came up as feedback from two-to-three man sniper teams, often the team spotter, required a weapon system that allowed him or her to support the sniper, using the weapon as a spotting scope, as well as taking a second-shooter role, doubling the accuracy and firepower of the sniper team, yet allow for close-quarter combat for security for the sniper team. The K-31 weapon system was designed with this goal in mind, allowing sniper teams to operate more effectively and independently on the field.
Exteriorly, the K-31 looks like any other weapon in service by both the Allies and the Federation. But internally, it is an engineering marvel. The K-31 is the smallest railgun fielded by both sides. The decision to use a railgun design was subject to much debate within both the designers, Lunatech, as well as the UESF. To build such a lightweight weapon, yet able to match contemporary sniper weapons already fielded within the UESF arsenal, such as the K-23, the basic coilgun design used in most contemporary sniper weapons were underpowered for the task, the weaponís size did not allow large enough capacitors or enough electromagnetic coils to allow the weapon to achieve the task it was designed for. Engineers could only think of three ways to overcome the issue. Either create a larger weapon, a fully gunpowder-based weapon, or a railgun. A larger weapon would defeat the purpose of the project, and a gunpowder based weapon was field-impractical, and gunpowder rounds were bulky, impractical and difficult to obtain. The railgun was the only way such a weapon would see the light of day. However, the railgun design posed itís own challenges. Before the projectís beginnings, the smallest railguns were those mounted on MBTs, or Main Battle Tanks. Even the first man-portable railgun, the K-23, was easily twice the size of the proposed K-31. Railgun recoil was also a major issue, since the advanced recoil dampening system of the K-23 was difficult to minituarize.
To overcome these problems, Lunatech engineers opted for the weapon to have a light round. The 5.56mm had been long forgotten in modern warfare circles, too light a round to penetrate modern body armour. However, this combined with the railgunís accelerating power allows the round to not only defeat modern body armour, but itís low mass dramatically reduces recoil and extends range somewhat. 5.56 rounds are reasonably common as well, even after being phased out from military use, most civilian-issued weapons still use them, both in powdered and powderless forms. The minituarized super-capacitors used in the K-23 were brought over to the K-31, and lightweight, yet durable firing rails were developed from the same technology used in the K-23, allowing for full semi-automatic firing. A simple scope system was developed by FENLAS Optical Co., with minimal computer-assisted systems and simple optics to keep manufacturing time and costs down. Finally, a low-weight metal casing protects the delicate firing rails and electronics in the weapon, yet allows easy access for quick rail-changes in the field, and has multiple RIS points to mount accessories such as bipods, close-in LAMs or such. A suppressor is also shipped with the weapon, dampening the loud noise and bright flashes attributed to railgun fire.
K-31s were praised by the infantrymen that served with the weapon during the latter part of the Sol War, due to the portability and power of the weapon system. Call for improvement came as soldiers often had issues with the rail-changing procedure, since most light infantry teams lack experience in handling railguns. The weaponís weight was also subject to criticism, although being small in size, it was quite hefty for a weapon. Weapon recoil was also an issue, an inheritant attribute in the railgunís design. However, the K-31 was considered a success, and will continue itís service in the United Earth Space Forces for the foreseeable future.
Sorry for the bad writeup, I'm just not in the mood. Just moved in to a rented room near the uni, so I have little to no time in doing these things.
Inspired by the real-life SR-25 rifle.