Cannone-Mitragliera da 37/54 (Breda)

The Cannone-Mitragliera da 37/54 (Breda) was a 37 mm automatic anti-aircraft gun produced by the Breda company in Italy.

It was used by both the Regia Marina and the Regio Esercito during World War II, with the former using it as the standard light anti-aircraft weapon on its battleships and cruisers. Nazi Germany used captured weapons after the surrender of Italy in 1943.

Design
The Model 1932 was water-cooled, but the subsequent Models 1938 and 1939 were air-cooled; the gun was fed by a flat magazine holding six rounds, but it was possible to load them one after the another to maintain a high rate of fire. It was possible to select alternate rates of fire, from 60 to 90 to 120 rpm. The twin Models 1932 and 1938 mountings were very heavy and required a strong supporting structure; the single Model 1939 (fitted on the Andrea Doria-class and Littorio-class battleships) was instead a single collapsible mount, which also had much less vibrations than its predecessors thanks to the addition of an equilibrator, and for this reason it was possible to fit it on small warships.

Performance
Although appreciated in the Regia Marina, overall this gun was of limited efficacy because of its gas-operated action (which reduced its rate of fire) and its substantial vibrations (due to their non-recoiling mounting) which impaired accuracy; instead the single collapsible model, which largely obviated to the latter issue, was seen as a definite improvement, while still being rather heavy and with its production being insufficient to satisfy the needs.