British 455 MK I & II

[Tascosa Joe]

Do any of you have case dimensions of these cartridges?  My copy of "Cartridges of the World" has them listed but no dimensions.   

[Baltimore Ed]

Here you go Joe.

[Sir Charles deMouton-Black]

My copy of the 3d ed. of COTW shows both dimensions. The Mk II shows a case length of .77 in. and a slightly larger rim diameter of .535.

As most Webleys have tapered, not stepped, chambers I can get away with using a .45ACP LEE case trimmer when doing "case conversions" to the Mk I case. The difference is only .02, (.89 to .87). The PITA is the thinner rim thickness!

[RattlesnakeJack]

It is my understanding that the diagram posted by Baltimore Ed shows the SAAMI specs (maximum?) for the .455 Colt cartridge, which was effectively a North American commercial version of the Mark I Webley cartridge, although expressed dimensions do seem to vary slightly.

Here are diagrams from the British War Department's "Treatise on Ammunition", which give "high" and "low" acceptable dimensions.  The Mark I diagram is from the 1902 edition of the Treatise, the Mark II diagram is from the 1905 edition -



       



For comparison, here is a composite of digrams from Dowell's "The Webley Story", for the Mark I and II bullets and the cartidge case used for the Mark I cartridge and the shortened version used in the Mark II cartridge (and subsequent cartidge versions) -

[Tascosa Joe]

Thanks to all.