50

Year 50 (L) was a common year starting on Thursday (link will display the full calendar) of the Julian calendar. At the time it was known as the Year of the Consulship of Vetus and Nerullinus (or, less frequently, year 803 Ab urbe condita). The denomination 50 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years.

This article lists firearm cartridges which have a bullet in the to  caliber range.