In the mid-1930s the UK was working on a new naval AA gun system to replace the 2pdr Pom Pom, designated the 1 1/2 pdr Mk V. The calibre was 35 mm and it fired a 680 g projectile at 790 m/s (1.5 lb at 2,600 fps). The project was cancelled in 1937 when it was realised that the planned 8-barrel mounting would weigh even more than the octuple 2 pdr.

Does anyone have any more information about this gun system or its ammunition?