While the majority of Systems Protectorate Forces are drones, human Infantry are occasionally required, and with them, conventional assault rifles. The Mk. 61 MAR or " Protectorate railgun" fills that role, serving as a standard issue long arm for Police, security guards, and officers in the field. Assault troops and Special Forces, on the other hand, carry the larger Mk. 86 OICW, which combines a Mk. 61 action with a semiautomatic 25mm guided antimatter missile launcher. Mass produced and issued in the thousands, Mk. 61s are by far the most common long arm in Known Space, used by both the Protectorate and rebels, as well as the militias of some Free Systems.
The Mark 61 MAR is a solenoid-actuated, fully automatic, rifled magnetic accelerator weapon. Its action works as follows:
1. barrel is pulled backward, stripping a slug from the magazine into the chamber.
2. an electric current from the capacitor banks is pulsed through the "rails" printed onto the barrel, expelling the slug at either ~Mach 5 or just below the speed of sound (this allows the weapon to fire in almost complete silence, but significantly decreases power compared to the supersonic setting)
3. The solenoid propels the barrel forward and back, stripping another slug into the chamber.
4. The process repeats.
The MAR fires a 10x35mm hollow-tipped, tungesten cored, pointed steel slug from a 30 round detachable polymer magazine, capable of defeating most conventional body armor and with sustained bursts even the powerful Combat Exoskeletons and Infantry Drones of the Protectorate Military. It's barrel is made of ceramic composite surrounding a rifled steel inner barrel on which 6 electromagnetic rails have been printed by magnetic nanoparticle printing. This is mounted within a solenoid which moves the barrel to cycle the action. The weapon's body is made of an advanced nano-composite, the interior of which is printed with the capacitors and circuitry which make the weapon function. Mounted ontop is a carry handle with built in backup iron sights in case of helmet failure, a laser sight/rangerfinder, and a digital "scope" which connects wirelessly to a solider's eyepiece or helmet. The weapon also has a folding stock and magnetic hardpoints on the sides, top and bottom for mounting equipment, such as guided missile launchers, sonic rams, forgrips or laser cutters.
Like all Protectorate weapons, the Mark 61 incorporates an advanced Identify Friend-Foe system, which both prevents the weapon from firing in the hands of a non-authorized user, and prevents the weapon from firing if it is pointed at any Protectorate Personal or Drones. This system was first designed in 2056 for American police weapons, and modernized in 2167 by "Levy" Artes'ranna, a Follower savant working in the Protectorate's Smart Weapons division, now gone rouge. Normally, this would make the Mk. 61 useless to rebels, but with Levy's help a countermeasure was developed which allows anyone to use the weapon against anything, with a bit of reprogramming. Free Systems programmers have also cracked the program locks, and blackmarket "cracked '61s" go for a premium on some Protectorate worlds.