Chain of 16 rounds.
Canadian made 20x102mm M55A2 cartridge used on the M61 Vulcan rotary cannon for use on the F/A-18 fighter jet. Both the projectile and case were made at Industries Valcartier Inc (IVI) who produce much of Canadas military ammunition.
The M55 target practice (TP) projectile consists of a hollow steel projectile with a press-fit aluminum nose plug and contains no energetic materials. This example was produced in 1973. The M103 case is made from brass and would have been fitted with an electric primer.
As standard with 20x102mm cases there is no headstamp, all markings are in ink on the case wall.