FP-45 Liberator Pistol 

/ forgottenweapons
The Liberator is one of those interesting artifacts of WWII; an extremely simple single-shot .45 caliber pistol made by the boxcar-load (a million, specifically) with the intention of being dropped en masse across Europe to promote civilian sabotage against German occupation forces. They were manufactured by the Guide Lamp division of GM in record time - just 10-11 weeks for a literal million-gun production run. However, as they were being manufactured, shipped, and put into storage the motivation behind the project largely evaporated. British SOE ultimately decided not to distribute any in France, and only distributed a small number to partisans in Greece.
In the US, the Army stockpile of Liberators was transferred to the OSS, and a fair number were actually distributed in India, China, and the Philippine Islands - although they did not ultimately have any measurable impact on the war effort.