British Stamp Proof Mark 3 character inspector badge under crossed swords

The English Probing Mark applied to a weapon, confirming the successful completion of Trials involving the firing of cartridges with a greater force than standard projectiles. It varies depending on the powder used in the test (black or smokeless, otherwise known as nitro) and the type of weapon on which it was applied.

Used in Birmingham between 1951 and 1974.

Type of confirmation: Indication of the date of testing, the letter on the left was A-1951, B-1952, etc. (without I), the letter on the right was the abbreviation of the city of Birmingham, the number on the bottom was the number of the inspector conducting the test.