The Westley Richards site can give you the date of manufacture if you enter your serial number.

Does anyone know how accurate it is - some dates seemed plausible eg 1926 for a 318 but I got 1915 for a 14ga and 500/450 No2 Muket cape gun which seemed rather late and 1888 for a 303 ie the year of its introduction as a military cartridge (according to COTW).

thanks,

mike