Cannone-Mitragliera da 37/54

• Name — Cannone-Mitragliera da 37/54 (Breda) • Origin — Italy • Type — Anti-aircraft gun • Is Ranged — yes • Is Explosive — yes • Is Artillery — yes • Used By — Kingdom of Italy Nazi Germany • Wars — World War II • Manufacturer — Breda • Production Date — 1932–45 • Variants — Modello 32, Modello 38, Modello 39, Modello RM39 • Weight — 277 kg (Modello 38 without mounting) • Length — 3.28 m • Part Length — 1.998 m (L/54) • Cartridge — Fixed QF 37 x 232mm SR • Cartridge Weight — 1.25 - (High-explosive shell) • Caliber — 37 mm • Action — Gas operated • Rate — 60-90-120 rpm • Velocity — 800 m/s • Range — 4000 m • Max Range — 7800 m • Feed — Automatic • Elevation — −10° to +90° (single mounts); −10° to +80° (twin mounts) • Traverse — 360°

The Model 1932 was water-cooled while Models 1938 and 1939 were air-cooled. The gun was fed by a flat magazine holding six rounds which could be loaded one after another to maintain a high rate of fire. It was possible to select alternate rates of fire, either 60, 90 or 120 rpm. The twin mountings for Models 1932 and 1938 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. This meant it could also be fitted on smaller warships. Ship classes that carried the Breda 37/54 include: * * * * * * * * * The Breda 37/54 was also fitted in the CANSA FC.20bis ground attack aircraft prototype in its variant Model 39 37/45.

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 eliminated the latter issue, was seen as a definite improvement, while still being rather heavy and with its production being insufficient to satisfy the needs.

• Country — Gun Model — RPM — Projectile Weight • Cannone-Mitragliera da 37/54 (Breda) — 60-120 — 0.82 kg • Nazi Germany — 3.7 cm SK C/30 — 30 — 0.74 kg • Canon de 37 mm Modèle 1925 — 15-21 — 0.72 kg • 37 mm Gun M1 — 120 — 0.61 kg • Nazi Germany — 3.7 cm Flak 18/36/37/43 — 150 — 0.64 kg • 37 mm automatic air defense gun M1939 (61-K) — 160-170 — 0.73 kg • QF 2-pounder naval gun — 115 — 0.91 kg • Bofors 40 mm gun — 120 — 0.9 kg