High Quality Content by WIKIPEDIA articles! Wonder Nine is a term coined by firearms author Robert Shimek which then became popular in American firearm-related magazines during the 1980s. It refers to any handgun that is chambered in 9x19mm Parabellum and has a double stack magazine, as well as a double-action trigger for at least the first shot. Examples would be the Beretta 92, Glock 17, CZ-75, and other such handguns. The simplicity of being able to fire the first shot just by pulling the trigger, a much-desired feature of double-action revolvers, combined with the high ammunition capacity (13-18 rounds, more than double what a revolver holds), are the "wonderful" features of a wonder-nine.