page_title: 25 mm automatic air defense gun M1940 (72-K)
section_title: Breech and automatic feeding mechanism
hierarchical_section_title: 25 mm automatic air defense gun M1940 (72-K) / Technical details / Breech and automatic feeding mechanism
caption_attribution_description: 25 mm 72-K gun displayed in Saint Petersburg Artillery Museum
context_page_description: 25 mm automatic air defense gun M1940 (72-K) was a Soviet 25 mm caliber anti-aircraft gun used during the Great Patriotic War. The gun was developed from the end of 1939 to the beginning of 1940 at 8th Kalinin Artillery Plant under the guidance of its Chief Designer Mikhail Loginov, supervised by Lev Loktev. The cannon was given the factory code 72-K before being accepted into service by the Red Army as the 25 mm automatic air defense gun M1940.
  The gun borrowed a number of features from the older 37 mm automatic air defense gun M1939, such as mounting the gun on an integral four-wheel chassis. The gun itself generally satisfied the Army, and its ballistic performance was considered state-of-the-art on the world level.
  The 72-K was designed for anti-aircraft defense for infantry regiments, occupying a place between the large-caliber DShK and the more powerful 37mm 61-K. However, due to difficulties in mass production, the 72-K did not reach the Red Army until the second half of the war.
context_section_description: The 72-K was equipped with a vertically falling wedge-shaped breech, which moves up and down in a slot as the weapon cycles. The gun cradle on the left of the breech has a "copier" that automatically unlocks the breech, near which a manual unlocking handle is also placed. The bolt consists of a locking mechanism, the firing pin, an ejector and a "copier", which allows for both automatic and single firing. The weapon would refuse to fire (with one last shell in the breech) should the loader fail to load another clip into the feed tray as the previous is expended. Firing would resume as soon as the next clip is loaded. The weapon is expected to be fed continuously as it fires from 7-round clips manually loaded to the feeding tray. Uninterrupted cyclic firing is possible so long as ammunition remains and the barrel does not overheat.
caption: Breech of the 72-K
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