These Little Atom 2mm pinfire cap gun rifles were imported from Japan by G & S Mfg. Co., of Nashville, Tennessee beginning in 1950. They sold them in gas stations and convenience stores across the country.
They are much harder to find than the pistols and these examples come in their original box with an original cartridge extractor.
These examples have a fluted barrel suitable for firing blank cartridges.
For more information please read the full article on these: 2mm Pinfire Guns and Cartridges