In reply to Gecff, New Zealand,Heres a couple of really good ref.Books with very practical guidelines on English, Scottish,Welsh, Irish,and Continental Guns.Forgot to thank Jim Legg for for the 'Plug"(Lobster Pound' Shore Rd.C/Neddick,5pm.New Keg of 'Harp Draught' will be Tapped' Thanks Jim...Des Mills, Actioner@ Purdeys 1950s,"Amateur Gunsmithing" 1968..G W Spalding "The Craft Of theGunsmith" 1986..and the latest"Tha Art of Gunsmithing The Shotgun" Lewis Potter,2006. Carol@ Gunnerman, has these Books,shes listed on The Doublegun Book Rack..C/C(still able to stand @ the workbench and balance a'Pint' while Chequering)