From an old IAA Forum discussion, the .45 Enfield cartridge was loaded at the request of the Canadian Northwest Mounted Police for their .476 cal Enfield revolvers. The NWMP had a problem with the recoil of the original Enfield loadings, so Dominion Cartridge Company loaded the same case with a lighter bullet for them, with a specific headstamp. (Erlmeier, Brandt Ref. 434).
