Hi, I found this recently on a former British island with my metal detector. It has some interesting markings on the headstamp and I'm not sure if it is a blank or whether it was intended to be used for launching a grenade. The length is approximately 2-3/16" and the diameter of the base is approximately 1/2". I can see an "R", "/|\" (type design), and an "L" at 12, 1:30, and 3 o'clock. A "C" or an omega at 9 o'clock. And the Roman numerals "IV" at 6 o'clock.Any info you can provide would be greatly appreciated. Thanks!