The M1947 Johnson auto carbine, nicknamed Daisy Mae by its creator, is a very rare prototype American battle rifle.
The auto carbine was designed due to Argentina getting interested in the weapons made by Melvin Johnson. However, after Johnson showed the weapon to the Argentinian army, they rejected it. Details of the weapon are very sketchy, and it is said that only five were made. Due to the rejection, the weapon never got past the prototype stage. Despite this, it is said that one of these auto carbines was used in World War II.