Browning Auto-5 is the oldest semi-automatic shotgun in the world. Designed by Browning in 1900, it utilised recoil to recock and feed next shell into chamber. Some sources claim, that Browning considered this shotgun to be his crowning achievement in firearm engineering.
Browning had offered the design to both Winchester and Remington for production, but was rejected by either, and finally had resorted to Fabrique Nationale productions in Belguim, which manufactured this outstanding weapon for almost a hundred years. Ironically, Remington ended up manufacturing Browning Auto-5 shotguns by license during 1940s.
Nicknamed "humpback" for characteristic angular rear part of receiver, Auto-5 were successfully used during both World Wars as trench guns. Similarly, they were often used by USA troops in Vietnam. Since they were not officially issued, soldiers had to procure Auto-5 through private means. Many did, and it was highly sought after and coveted, being often found superior to M16 in the jungle environment.
Manufactured in 12, 16 and 20 gauge, with variety of barrels and stocks, Browning Auto-5 were and still are highly efficient guns. Since the production had ceased, Browning Auto-5 shotguns began being considered collector`s pieces, commanding high prices.