The 6mm Thermos Bottle was designed by M.L. McPherson in 1999. It is based on shortened Lazzaroni Patriot case (or 416 Rigby). The purpose of this �Thermos Bottle� design was to make a fat and short cartridge, able to handle the heavy 115 grs VLD bullets for 1000-yard benchrest competition. From a 30 inch barrel, it generates approx 3000 fps. 

This text is based on information from “Cartridges of the World”, Hodgdon reloading manual, the cartridge designer and/or own resources.