Vollmer M35

The Vollmer M 35 (also known as Vollmer-Maschinenkarabine or MKb 35) was a series of experimental automatic rifles developed by Heinrich Vollmer in the interwar years. They were chambered in an intermediate cartridge that was co-developed with Gustav Genschow and Co. (GECO) starting in 1934, under a Heereswaffenamt contract.

The M 35 was a gas-operated design, reminiscent of an earlier semi-automatic design of Vollmer—the 7.92×57mm Selbstladegewehr 29 (SG 29). Trials with Vollmer's Maschinenkarabine were conducted as early as 1935 at Biberach and later at Kummersdorf. The early version had a 20-round detachable box magazine and could fire at a rate of about 1,000 rpm. Development continued with the improved versions M 35A, M 35/II (1937) and M 35/III until 1938. The later versions had purposefully reduced rate of fire to only about 300–400rpm. It weighted about 9 and 1/2 pounds (4.2 kg) and was bout 38 inches long (96 cm). About 25 prototypes were manufactured for testing. The gun was apparently very expensive to manufacture, costing apparently 4000 Reichsmarks, although this was the unit cost for the prototype series.

The cartridge developed also had several variants 7.75×40.5 mm, 7.75×39.5mm, and possibly a 7.62mm version as well, and had approximately 55 mm total length. (The actual calibre was apparently 7.9mm, with a bullet 8.05mm in diameter. ) Muzzle velocity was about 700 m/s (2,280 feet per second). The boat-tailed bullet weighted 140 grains (9 grams).

Ultimately, Nazi Germany would adopt a different intermediate cartridge and service assault rifle—the MKb 42 series leading to the Sturmgewehr 44. The GECO M 35 cartridge bare more dimensional similarity to the Soviet 7.62x39mm M43 cartridge than with the German 7.92×33mm Kurz used in the Sturmgewehr.