And some tech data.
This cartridge case was used for all the different types of ammo used in the CF (HESH-T, SH Pract, Smoke BE, Canister Shot and Blank).
The case, which is identified by its Drawing Number RW175, is manufactured from brass by the deep drawing process. It is a tapered and necked design, parallel at the mouth and conforms with following maximum external dimension:
Overall length ... 231mm (9.115inches)
Base diameter ... 96.6mm (3.085 inches)
Mouth diameter ... 78mm (3.074 inches)
Mouth diameter (internal) ... 75.5mm (2.98 inches)
Weight (empty cartridge case) ... maximum 1.3kg (2lb 14oz)... minimum (1.2kg (2lb 10oz 10dr)
The primer hole in the base of the case is counterbored and threaded to receive the No. 15 percussion primer.
Permanent marking stamped in the base consists of the following:
76mm ARMD C (caliber and role, ARMD C meaning Armoured Car)
RW175 ( drawing number)
CF ammunition lot number