Every armed conflict that has involved the United States since the Revolutionary War has used “shotguns” in some manner.  Combat today is no exception, but the real drawback to arming Soldiers with shotguns in that they become dedicated weapons having limited range and utility compared to rifles, so that shotgun armed Soldier is unable to serve the same general purpose role in battle as our traditional riflemen.  So the development from a “dedicated” shotgun into a modular accessory shotgun was long ago recognized by KAC designers.  Attached to a host weapon Carbine or Rifle in the exact same manner as the M203 with KAC's “QD” Latch Assembly, the Masterkey allows the Soldier to serve in two completely different combat roles without over-burdening him with two “complete” weapons.

The KAC 12 gauge Masterkey Shotgun can be mounted under standard rifles as a breaching tool with special ammo.  It is also mountable to a Standalone Module from KAC.

KAC 12 Ga. Masterkey shotgun is designed to provide a powerful built-in door breaching tool to supplement assault rifles.  Soldiers in CQB/CDC environments can enhance their combat performance by strengthening their assault rifle capabilities with this powerful addition, turning two weapons into one flexible solution.  KAC 12 Ga. Masterkey has the same mount ability as KAC M203.  This system consists of a Remington 870 shotgun that can be mounted onto a M4 rifle in an under-barrel configuration.  The shotgun has a 3 round capacity and should only be operated when attached to a host rifle or the Standalone Buttstock module.  When firing the Masterkey, the M4 magazine will be used as a pistol grip.  Currently, KAC 12 Ga. Masterkeys are deployed to select groups of elite troops.

Specifications
Caliber                                 12 Gauge
Magazine Type/Capacity         3 Round Tube
Weight (w/o magazine)           5 lbs, 4 Oz
Length with stock extended    17 1/4”
Barrel Length                        9.5”