The 2mm Kolibri (also known as the 2.7mm Kolibri Car Pistol or 2.7×9mm Kolibri) was the smallest commercially available centerfire cartridge, [3] patented in 1910 and introduced in 1914 by Franz Pfannl, an Austrian watchmaker, with financial support from Georg Grabner. It was designed to accompany the Kolibri semi-auto pistol or single-shot ...