The FP-45 Liberator was an inexpensive single-shot pistol designed by the U.S. military during World War 2 to serve as a disposable weapon. Though described as an 'assassination weapon' some historians bristled at the connotation, indicating that the intent was to provide ultra cheap 'insurgency weapons' which could be dropped behind enemy lines to friendly forces. The simple design and single shot capacity would ensure that the weapon be regarded as relatively useless by any enemy military (firing a .45 ACP round from an unrifled 4-inch barrel, the Liberator's effective range was around 3 yards, and the all-metal body and locked breech means the weapon can cut the shooter's hand when fired if they are not wearing gloves), but could be used as a last ditch defensive weapon or to procure better weapons from enemy forces, which was the Liberator's primary purpose. The weapon was made in utmost secrecy, with instructions using non-firearm terms such as "spanner" to describe the parts and a deliberately misleading designation ("FP" for "Flare Projector"). 25,000 were dropped to the French resistance, 100,000 sent to China, and a few thousand airdropped in Greece, but most of the remainder of the production run of around a million guns were destroyed after the war.
The Liberator is an extremely simple twist-lock breech weapon without even an extractor mechanism; while it can store 5 additional .45 ACP rounds in the grip, this is just a compartment and does not feed into the weapon. Reloading the weapon requires the spent casing first be manually forced out of the barrel from the front, with a wooden dowel rod provided for this purpose. This rather infamously resulted in the only gun in history that took longer to reload than it did to manufacture. This is a mild exaggeration: it is based on dividing the number of guns produced by the total manufacturing time for all of them (11 weeks to make 1,000,000 guns, working out as a gun produced every 6.7 seconds), rather than the time to make a single gun.
The FP-45 Liberator and variants can be seen in the following films, television series, video games, and anime used by the following actors: