McClean Prototype Automatic Rifle
During the early 1900s Samuel McClean had developed a large, truck-mounted, 37mm auto-cannon but following the failure of this project McClean began development of a rifle-calibre machine gun. The result was a series of complex designs which never fully matured.
McClean, a medical doctor by training, had previously developed a series of firearms including a semi-automatic pistol, rifles and a shotgun. He is perhaps best known for designing what would eventually become the Lewis Gun, he was certainly a talented and prolific inventor with over thirty, predominantly gun related, patents to his name by 1920.
This gun, however, is one of McClean’s attempts to develop a viable automatic rifle. Believed to date from 1918-19, it is certainly smaller and less complex than his earlier water-cooled prototypes. The gun pictured above is incomplete but does have a wooden butt-stock and front grip. The gun has a pair of triggers, one for semi-auto and the front trigger for fully-automatic fire. What isn’t present is the weapon’s magazine. When examining the photographs above its worth noting that the gun itself has been rendered inoperable by cutting away part of the receiver, to fulfil US laws regarding machine guns.
A couple of contemporary photograph are, however, reproduced in Henry Chin’s book on machine guns. Chin’s book remains the best available resource concerning this prototype.
In the photograph above we see Samuel McClean firing his automatic rifle from a bipod. We can see that the magazine is a large circular drum-like assembly which surrounded the receiver of the weapon. To load the magazine the weapon itself musthave been passed through the centre of the magazine until it interfaced with a ratchet system just ahead of the chamber. As a result the gun feeds from the top of the receiver and ejects spent cases from the left. A large magazine release catch with a hook is just in front of the trigger guard. According to Chin the operating mechanism of the weapon was very similar to McClean’s auto-cannon.
McClean’s 1905 patent for his auto-cannon showing the gun’s gas operating system. (source)
Like the auto-cannon the automatic rifle uses a large number of small interrupted-threads to lock the rotating bolt in battery. Below the barrel is a gas system, with a piston inside a large gas cylinder with a main spring inside as in the larger cannon.
According to Chin the gun was demonstrated for the US Navy in May 1919 at the Naval Air Station in Anacostia, D.C. Chin notes that while the weapon operated satisfactorily the Navy showed no interest in the design with the M1918 Browning Automatic Rifle already in service and World War One over their was no need for another automatic rifle.
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Images Source
The Machine Gun, G.M. Chinn, (1951) Our friend Ian over at Forgotten Weapons has also taken a look at the gun and shows some of the working parts.
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