.310 inch Cattle Killer

This cartridge was used by the army for the humane destruction of cattle or horses. Prior to this the .4555 inch Webley round had been used.

"Cartridge S.A. Ball .310 inch Mark Iz" was approved to design IDW 4053 in November 1917 and shown in Lists of Changes Paragraph 19944 dated February 1918. It was originally called "Cartridge Greener's Cattle Killing Mark I" and in 1926 the title was changed to "Cartridge S.A. Ball .325 inch Mark I" and finally changed to "Cartridge S.A. Ball .310 inch Mark Iz Horse Killer".

The case was rimmed with straight sides and had a Berdan primer. The headstamp was usually "KYNOCH .310 C.K."

The bullet was of lead alloy and weighed 125 grains.

The propellant was about 5.3 grains of nitro-cellulose/