The Colt Defender Mark I is a prototype American shotgun.
Originally created in 1967, Robert Hillberg, the designer of the weapon, thoroughly tested his weapon out before beginning to seek a manufacturer; his design proved to work so well that few changes had to be made before production. Colt showed considerable interest in the weapon system, but said that they had to conduct a market survey to see if there was any interest in this weapons platform before full production could begin.
Colt then demonstrated the weapon to various agencies, all of which were impressed with the weapon's functionality and compactness. However, the Defender Mark I was a case of bad timing; due to the 1969–70 recession in the United States, a weapon of this type was disallowed entry into service, and the project was completely shelved by 1971. No surviving examples are known to exist.
The Defender Mark I is an eight-barreled combination gun of sorts, with the eight barrels built around a double action revolver-like mechanism fired by a hammer. It has an alloy steel receiver and is finished in epoxy paint. The Defender Mark I also had two triggers; the rear trigger fired off the magnum shells, while the second trigger in front was used for "instinctive firing".
- First variant
A heavily simplified version with no special features.
- Second variant
Had a barrel selector which could be actuated by turning a knob which adjusted the rotating striker on the hammer.
- Third variant
Had a tear gas grenade receptacle placed in the middle of the eight-barrel cluster. The tear gas grenade could be fired by pulling the front trigger.
- Fourth variant
A combination of the second and third variants, in which it had both the tear gas selector and barrel selector.