Depending on age it could be one of about three. The very earliest used the Eley 1B primer now long obsolete. (Separate primer much like a muzzle loader cap with a separate anvil and very fiddly). They then used the Eley Surefire primer. Also obsolete but can still be found in the U.K. in a few older type gunshops who may have some somewhere if you are lucky. I still have a few but cannot be posted. The later ones also used an Eley Surefire but this time it was in a copper cup. If in this later type (I think they were only in buff coloured paper cases and of the last loading circa 1976) then the whole part can be pushed out and a 209 type primer used. If they are in red paper cases then 10 to 1 they will only accept the Eley Surefire primer and trying to punch it out to try to accept the 209 primer will just result in a case with a bulged head and ruined. If you can post a picture or e-mail me one of the case and the head stamping showing the primer I should be able to tell. Search for the Eley Surefire primers. They came in orange tins of 100 with a screw on lid. Some may have found their was Stateside. Good luck. Lagopus.....
