.577/450 Martini-Henry question

The .577/450 shown on the left has a slight step just above the rim. It probably won’t show very clearly in the scan but it is about 4mm deep and increases the case diameter by about 1mm. Presumably it is there intentionally but why?


If you look in the old Eley or Kynoch catalogues you will see that the drawn brass case Martini and Snider rounds are of this configuration. Presumably it followed the contours of the original coiled brass cases and the raised portion was the equivalent of the base cup of the rolled case.

Check the diameter of the two cases you show. I suspect the diameter immediately above the rim will be the same and the body of the left hand case will be of slightly smaller diameter than the “normal” case.


Thank you Tony. Would this be for military or commercial use…or both? It has no headstamp.