The Gerät 06(H) (Halbverriegelt, lit. "Half-locked"), often erroneously known as the StG.45(M), was a German prototype assault rifle that was designed by Wilhelm Stähle and produced by Mauser during the closing stages of World War II. Utilizing an early roller-delayed blowback system, the Gerät 06(H) led directly to the development of the post-war Heckler & Koch G3.
History[]
The Gerät 06(H) was developed from the earlier Gerät 06 assault rifle, modified to use a rolled-delayed blowback mechanism that allowed for the gas system to be omitted. The Gerät 06(H) was to serve as a cheaper alternative to the StG 44, which was becoming increasingly difficult to produce with Germany's straining resources; the Gerät 06(H) was said to cost 40 Reichsmarks compared to the StG 44's 70.
Only 30 incomplete rifles were produced by the end of the war. Some examples were captured by the British and Americans, and a few remained in the possession of ex-Mauser engineers, such as Ludwig Vorgrimmler, who smuggled them out of the country and continued work on the design. Vorgrimmler further developed the Gerät 06(H) system at AME in France and CETME in Spain, resulting in the design of the CETME 58. The CETME rifle was itself later developed into the highly successful Heckler & Koch G3.
The designation StG.45(M) has been popularly attached to this gun, however there is no historical basis for this name. No contemporary documentation refers to the Gerät 06(H) as a Sturmgewehr, and since it was not adopted for service, it never earned an official military designation. Altenberger, one of the chief designers on the Gerät 06 project, referred to the gun as the "MP45" when questioned by Allied officers after the war.
Design[]
The Gerät 06(H) was almost identical to the Gerät 06, bar its half-locking roller-delayed blowback mechanism. Despite the lack of a gas piston compared to the older Gerät 06, the design required for the bolt to move while the bullet was still in the barrel and the spent case was fully pressurized; the use of traditional chambers caused case heads to separate during testing. The solution was the change from a traditional chamber to a fluted chamber, where longitudinal grooves were cut into the chamber, allowing gases released from combustion to float the case, assisting in extraction. This scorched the cartridges in a unique manner which was characteristic for later weapons made by Heckler & Koch using the same roller-delayed blowback principle.