There's a list of obsolete calibers produced by the home office, which I believe is updated from time to time. Theres info here:-
http://www.david-squires.org.uk/Antiques.htm
Thanks, Mark!
A good selection of calibers there: enough to keep any collector occupied.
Glad to see I could keep my pinfire revolver if I move to England.
Jim
UBC's Police Pistol Manager
"Nasty, noisy things, revolvers, Count. Better stick to air-guns." Sherlock Holmes, The Adventure of the Mazarin Stone