7.75 X 40 M.35 GECO

  

The German Heereswaffenamt (military weapons development establishment) contracted with Gustav Genschow & Co. (GeCO) during 1934 for the development of a smaller, lightweight cartridge. The Vollmer-Maschinenkarabiner 35 or M35 was developed in early 1935 when GeCO contracted with Heinrich Vollmer for the development of a rifle capable of firing this cartridge. Vollmer had been working since the early 1930’s on a submachine gun/semi-auto rifle, the Selbstladegewehr 29, chambered in 7.92x57mm but that design was rejected.

The new rifle was a breakthrough in one regard, namely that it was a select fire carbine capable of full automatic fire, something that has proven elusive to all other designers at that point in time. Furthermore, they achieved the effect of miniaturization which is a big benefit to any soldier carrying ammunition in a battle scenario. Tests during July 1935 showed that the rifle was able to fire at a rate up to 1,000 rounds per minute in full auto mode, while not weighing more than a single shot rifle. Some teething problems were encountered that lead to a second prototype, the M.35A. The Heereswaffenamt requested some changes to the design to bring the rate of fire down to 400 rounds per minute and to allow for mass production. During further tests, some feeding and extraction problems were encountered but the rifle was modified and during 1936-37 further tests were done where 13,000 round were fired in full auto with no stoppages.,

The M.35/III was the final version and testing was done on the 21st of September 1938. The Heereswaffenamt requested 25 carbines for further trials. These were handmade by Vollmer’s own firm, Vollmer- Werke Maschinenfabrik and the M35/IIIs were found to be extremely reliable. Testing continued into 1939 but the project was cancelled later that year. The war clouds were gathering over Europe and Germany invaded Poland in late 1939 and it was decided that the M.35 was too complex and expensive weapon to manufacture in large enough quantities and it would have required some extensive retooling at the weapons manufacturing plants, something nobody wanted in the middle of a war. The idea of a lightweight, select fire carbine with a simplified action survived that resulted in designs from Walther and Haenel to chamber the newly developed 7.92×33 Kurz that would use the famous StG-44.