Calico M100

The Calico M100 is a semi-automatic carbine chambered in 9x19mm, produced by Calico Light Weapon Systems from the 1980s. It features a distinctive high-capacity helical-feed magazine mounted above the receiver, holding 50 or 100 rounds. The M100 uses a unique delayed-blowback action with a roller-locked bolt. Its futuristic design and enormous magazine capacity made it a distinctive entry in the personal defense weapon market. The M100 was also produced in a select-fire variant for military and law enforcement. It was one of the few firearms ever designed around a helical-feed magazine system.