The 45 ACP chambering for the American Derringer Model 1 uses a moon clip to headspace rimless cartridges in the over-under barrels. A potent two-shot backup option. Type: Derringer Action: Break-Action Caliber: 45 ACP Capacity: 2 Year introduced: 1980, USA Weight: 15 oz Overall length: 4.82" Status: Active Intended use: concealed carry, backup