Different British 1924 0.5in Case?

[oldshotandshell]

Case (C) has me puzzled. Dimensions as follows. Length 81.5mm, Diameter head 18.47mm, diameter rim 18.15mm. Images below show it with an Italian 12.7 Breda case (A) and a British 0.5in Vickers case (B) in the middle. Crimps consist of three small stabs and a circumferential crimp. Berdan primer. Headstamps read 'R/|\L 1114A'. Any thoughts on identification would be appreciated.

 

[ydnum303]

Sorry for late reply, but only just come across this post whilst searching for something else!
According to the late Peter Labbett in his book "British Small Arms Ammunition 1864-1938, this was a case for the early "Cartridge Machine Gun Ball .5 inch Mk.II.z", and the 1114A was the Design Number. The round was approved for service in May 1925, after which it would have had "II.z" in the headstamp instead of the number. Quite a few cartridges of different calibres had the Design Number stamped on the case before final approval.

Roger.