This is an extremely rare example of the experimental 9.8mm Automatic Colt cartridge that was developed c. 1910 for use in the prototype Colt Model 1910 pistol, which Colt planned to market primarily in Eastern Europe to compete with Fabrique Nationale. The outbreak of World War I and a marketing deal between FN and Colt led to the Model 1910 and its interesting 9.8mm Auto cartridge never making it to full production, with only five prototypes of the pistol being believed to have been made, leaving exceptionally few examples of the pistol, as well as the cartridges, available on the collectors market. Constructed from brown cardboard, with a black-on-orange lid label and a green seal. The lid label bears a picture of the 9.8mm Automatic Colt cartridge, and is marked for 50 rounds, with the New Haven address below. Though the factory seal is broken, the box contains a full compliment of cartridges.