Author Topic: British 455 MK I & II  (Read 124 times)

Offline Tascosa Joe

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British 455 MK I & II
« on: September 06, 2019, 08:01:20 am »
Do any of you have case dimensions of these cartridges?  My copy of "Cartridges of the World" has them listed but no dimensions.   
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Offline Baltimore Ed

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Re: British 455 MK I & II
« Reply #1 on: September 06, 2019, 09:21:48 am »
Here you go Joe.
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Offline Sir Charles deMouton-Black

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Re: British 455 MK I & II
« Reply #2 on: September 06, 2019, 12:22:11 pm »
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!
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Offline RattlesnakeJack

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Re: British 455 MK I & II
« Reply #3 on: September 06, 2019, 06:35:59 pm »
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) -

« Last Edit: September 06, 2019, 06:37:31 pm by RattlesnakeJack »
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Offline Tascosa Joe

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Re: British 455 MK I & II
« Reply #4 on: September 06, 2019, 10:37:35 pm »
Thanks to all.
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