This tin has only one cartridge with it. The usual raised acorn headstamp from RWS Nuremberg made for Millard Bros, London.
Two layers of 25 rounds in cards. 11.2mm case length. Lead conical.
I remember shooting Milbro Jet air-rifle pellets in the 1960’s. Milbro was their trade brand.
How long was Millard Bros in business?