Specifications:
Weight: 5.7kg unloaded.
Length: 94.5cm
Barrel Length: 66.6cm
Height: 16.4cm w/o sights.
Cartridge: 20x100mm Grenade
Action: Gas operated roller locked V-bolt
Muzzle Velocity: 320m/s
Effective Range: Up to 3km.
Feed System: 9-round integral rotary magazine. 5-round clips.
Sights: Rear flip-up gradient with diopter, front open fixed post. Rail system.
History:
The GR-88 was conceived to fill a gap in the firepower of the infantry section in combat. In 10,379 (Sumerian Calendar) it was realized that the rifle grenade was unusable in Combat in Enclosed Spaces (CES) and the grenades available for the 20mm (Real value 18.4mm) shot guns were inadequate for sufficient explosive power on target. The GR-88 was thus designed as a multi-shot, semi-automatic large caliber rifle firing a larger, more powerful grenade. The result, issued to troops starting in 10,388, is the GR-88.
Design:
The GR-88 is a gas operated semi-automatic large caliber rifle intended for firing medium-velocity grenades across all ranges of the infantry-section's fire. The GR-88 uses a roller-locked bolt derived from most Sumerian combat rifle designs. The rifle is fed from a nine round fixed rotary magazine which feeds from five round stripper clips through a gate in the right side of the weapon. The total capacity is ten rounds, including one in the chamber. A firing-pink block safety is included preventing the weapon from firing unless the trigger is pulled, along with a grip safety which prevents the trigger assembly from being activated without the weapon being pulled. This allows the tenth round to be carried in the chamber safely. The rifle is of bull pup design with the integral magazine behind the grip and trigger assembly. The bolt recoils to a stop in the butt of the rifle, with a dampening spring acting vertically on a V-joint bolt to allow longer travel time in a shorter length. A magazine stop is included forward of the magazine which prevents a round from feeding in to the chamber when the bolt retracts when activated. Rounds can be removed from the chamber through one of two doors which act as dust covers, one on each side. When either door is open the round is automatically ejected out the open door by a spring loaded pin in the bolt. When both doors are open the pin is locked in to the bolt and the round does not eject, allowing for cooling or quick cleaning if needed. Rounds may also be inserted directly in to the chamber through the door when the weapon is empty or the magazine stop is activated. This allows different rounds to be loaded and fired when needed.
The GR-88 fires a special 20x100mm "caseless" grenade family which includes several special variants for various tasks. The round is "caseless" not in the conventional sense as its cartridge case is fixed to the round and stays on it in flight. When the round is fired the propellant in the base of the round burns through five ports in the bottom of the fixed case, pushing on the bolt and chamber of the rifle and moving the whole round down the barrel. In flight the fixed case aids in aerodynamics while residual gas emitting from the ports in the case acts as a base-bleed system to a small extent. This improves ballistic performance, allowing greater range and accuracy of the round. The round fires at around 320m/s and has a maximum range of three kilometers. Several types of rounds are available, including canister, flechette, armour piercing, flare, and a parachute-slowed reconnaissance round which includes a small digital camera for disposable observation. The most common rounds, however, are semi-armour piercing dual-purpose, and high-explosive, with their respective tracer rounds. The HE round is activated by a contact fuse which is enabled when the pressure in the case drops to sufficient levels to indicate the round has left the barrel of the gun. The HE round is a thin-walled round which allows all-round bursting. The SAPDP rounds have a delayed fuse which allows the round to penetrate light armour and detonate behind the armour. The round consists of an armour piercing cap which wraps around the rear explosive filler, acting as a secondary fragmentation element. The SAPDP rounds have the same safety fuse as the HE rounds. Rounds are delivered in five round disposable stamped metal clips. In the field many soldiers will re-group their clips to alternate HE and SAPDP in a single clip, and carry specialized rounds loose.
Fitted with a rail attachment system, the GR-88 can mount many types of optics, as well as use the built in sight. A forward folding mono pod is also included to assist in prone firing, and a folding heavy-wire shoulder shelf is included to keep the rifle propped on the shoulder of the firer.
Export
By virtue of an export and production agreement between Lyran Arms and the Dictatorial Republic of Sumer, the GR-88 is available for NS$4,700 each, purchase being available through Lyran Arms.
