British AA Guns

British anti-aircraft weapons came in two classes, light and heavy. The main gun in the light class was the 40mm Bofors, though 20mm Polstens and Oerlikons were issued. The heavy class was dominated by the excellent 3.7in with the old 3in being used to defend airfields back in Britain.
The guns equipped both light anti-aircraft and heavy aircraft regiments, the LAA regiments were usually all 40mm, but occasionally troops of light 20mm were added. The 3in and 3.7 were issued to HAA regiments. Late in the war when it came clear that the Luftwaffe threat had receded, many of the LAA regiments were reduced in size and many gunners were used as riflemen to replace losses suffered by the infantry divisions.