 A nearly identical carbine with an overall length of or greater is simply an unclassified firearm under Title I of the Gun Control Act of 1968, as the Any Other Weapon catch-all only applies to firearms under or that have been concealed.However, a modification intending to fire from the shoulder and bypass the regulation of short-barreled rifles is considered the unlawful possession and manufacture of an unregistered short-barreled rifle.In some historical cases, the term "machine carbine" was the official title for submachine guns, such as the British Sten and Australian Owen guns.