Door breaching has long been a technique relied upon by various law enforcement, special forces elements, and standard infantry to gain entry to otherwise inaccessible areas. Various systems have been devised over the decades to breach such obstacles as doors and, during the 1980s, the Knight's Armament Company (KAC) of the United States developed the "Masterkey" for this very purpose.
The weapon was essentially the primary working components of the classic Remington M870 pump-action shotgun and this was mounted under the forward section of a standard assault rifle such as the Colt M16. The reduced profile of the M870 reduced the amount of carried shells to four (with one shell being chambered) and, lacking any sort of stock or grip of its own, the magazine of the rifle doubled as the grip handle, providing access to the M870's trigger unit which was retained from the shotgun. The end result was an effective battlefield piece suitable for door breaching and one that added little length and weight to the rifle.
Notable operators of the Masterkey included United States Delta Force. The shotgun door-breacher concept continues today in such developments as the M26 Modular Accessory Shotgun System (MASS) produced by C-More Competition (and detailed elsewhere on this site).
(OPERATORS list includes past, present, and future operators when applicable)
Extreme close quarters use; trench-clearing; doorbuster; security.
Qualities of this weapon have shown its value to Special Forces elements requiring a versatile, reliable solution for the rigors of special assignments.
432 mm 17.01 in
432 mm 17.01 in
5.73 lb 2.60 kg
Manually-Actuated Pump Action System
(Material presented above is for historical and entertainment value and should not be construed as usable for hardware restoration, maintenance, or general operation - always consult official manufacturer sources for such information)
Rounds / Feed
3+1 rounds (one chambered)
*May not represent an exhuastive list; calibers are model-specific dependent, always consult official manufacturer sources. **Graphics not to actual size; not all cartridges may be represented visually; graphics intended for general reference only.
"Masterkey" - Base Series Name; modified Remington M870 used as underslung base weapon system.
Ribbon graphics not necessarily indicative of actual historical campaign ribbons. Ribbons are clickable to their respective campaigns / operations.
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Image from official Knights Armament Company marketing material.
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