Need help again, I have been using a new set of Hornady .450 nitro dies and new .450 3 1/4" Jamison cases. Kynoch .450 nitro ammo will very easily go into a .450 Purdey, .450 Holland and Holland, .450 Alex Henry and a .450 Nitro 1902 Webley, yet the new Jamison cases after full length resizing do NOT fit in any of the rifles. The bases of the Kynoch and Jamison mike the same as does the case mouth. The middle of the Jamison cases after sizing are larger than the Kynoch cases and prevent the cases from chambering. Do you think the sizing dies are suspect? New to reloading.
