Three barrels, three firing pins, 18 chambers

VIDEO

This nifty spanish revolver fired off three 6.35mm rounds per trigger pull. The recent trend of double barrel guns is not so recent.

VIDEO

UPDATE: I forgot to add the link. There is some disagreement about wether it fires more than one shot at a time. My interpretation of the three barrel/three firing pin design is that it does, the before mentioned link confirms this.