The Astra Model 400 (officially the Astra 1921) was the standard Spanish military service pistol from 1921 through the late 1940s. Chambered in 9mm Largo (9x23mm), it used an unlocked blowback action — unusual for a full-power pistol cartridge — relying on a heavy slide and strong recoil spring. The Model 400's chamber was dimensionally tolerant enough that it would function with multiple 9mm cartridges including 9mm Parabellum and 9mm Browning Long. Type: Pistol Action: Semi-Automatic Caliber: 9mm Largo Capacity: 8 Year introduced: 1921, Spain Weight: 35.3 oz Overall length: 9.25" Status: Discontinued Military use: Yes Intended use: military, collector, historical