calico m950
The Calico series are submachine guns (along with the civilian semi-automatic pistol and carbine versions) produced by Calico Light Weapons Systems. The M100/M110 series are fire .22 Long Rifle rounds, while the M750/M900/M950/M960 series fire 9x19mm. The 9x19mm versions were later renamed the Calico Liberty I, II, and III. All versions use proprietary helical box magazines with a capacity of 50 or 100 rounds mounted on top, and shell casings are ejected out the bottom similar to the P90.
While civilian semi-automatic sales have been limited and attempt to market the submachine guns to military and law enforcement have been unsuccessful, the Calico series are somewhat popular in science fiction due to their futuristic appearance.