This Eley string-tied packet is unmarked.
The green paper case is 44.5mm long with a lead ball? seated below the case mouth and held with a whitish wax or sealant. 7mm brass base.
ELEY’S Gastight Cartridge Case written on the case wall. No headstamp.
The pin is 10mm long which seems rather too long for use in a cane-gun?