Tags: Weapon.
The Ciener Ultimate Over/Under system is a modification of the Remington 870 shotgun by Johnathan Arthur Ciener. It is identical in purpose to the Knight’s Armament Company Masterkey or the accessory weapon configuration of the Remington 870 MPS. The system consists of a Remington 870 12 gauge pump-action shotgun mounted on a M16 or M4 assault rifle in an underbarrel configuration much like the M203 grenade launcher.