The Astra Model F was the final evolution of the Astra 900, a C96 Mauser lookalike. The Model F used detachable magazines and was select-fire, with a very effective rate reducing mechanism in the grip. It was adopted by the Guardia Civil in 1934, and 1,126 of the guns were produced in 1935.

Of those guns, 950 were delivered to the G.C. in June and the remaining guns remained at the factory, where most were seized by the Euzkadian government in August and September of 1936, with the outbreak of the Spanish Civil War. Unlike most of the Astra 900 series, the Model F was made in 9mm Largo. The Model F also used its own proprietary magazine (made in 10- and 20-round sizes), not interchangeable with either the Astra 903 or the Mauser Schnellfeuer.