455 Webley Nomenclature

[keithherrington]

I was curious about the bore diameters of guns chambered for 455 Webley, such as some Model 1917s. According to Wikipedia, the 455W has a bullet diameter of .454". This surprised me since so many of the British cartridges I'm familiar with are designated by their bore diameter, not their groove diameter (e.g., 303 British which has a .311"-.312" bullet diameter). Does anyone know why this cartridge is different?
Keith

 

[PJGP]

When the Mk I Webley Service Revolver was introduced to service the calibre was given as .441" (sometimes quoted as .442"); ie bore and not groove. The introductions to service of all the subsequent marks (II-VI) never mentioned calibre; only the differences from the previous Mark. Later drawings show the groove depth as nominally .005", giving a groove diameter of .451" or .452" as you prefer. The chamber mouths were nominally .450".

The introduction to service of the Mk I "Cartridge, S.A., Ball, Pistol, Webley" had a drawing of the round with the lead bullet diameter given as .455". The whole idea was to ensure that the black powder charge had time to build up pressure before the bullet reached the barrel throat. None of these dimensions were changed in subsequent guns or cartridges.

.455" was only ever mentioned in official nomenclature when the Mk VI jacketed bullet was introduced in 1939 ""Cartridge, S.A., Ball, Revolver, .455inch, Mk VI". Note that originally (from 1854) revolvers were known as "Pistol, Revolver" since they replaced earlier single shot pistols.

Peter

 

[glowe]

Here is an interesting history on 455s from IAA.

Those Confusing .455s - International Ammunition Association

 

[Jack Flash]

There aren't any M1917s chambered for .455 Webley unless they have been modified post-factory.


The ones you speak of are undoubtedly what Mr. Supica calls the .455 Mark II Hand Ejector 2nd Model. They are easy to spot as they have a 6-1/2 inch barrel as opposed to the 5-1/2 inch barrel on an M1917.

 

[Hondo44]

S&W split the difference with their barrels.

Their three models chambered for the .455 Mk II (Webley):
44 HE -1st Model chambered in 455,
455 HE -1st Model, and
455 HE -2nd Model

all had a bore diameter of .447" to .448"; groove diameter of .457' to .458".

 

[Texas Star]

I liked Peter's excellent post. Can he or others here explain the rifling differences between the Webley-Wilkinson M-1905 and the 1911 version? As best I recall, the main difference was just that the rifling direction changed. Anyone know why, and was the twist different?


Why were these deluxe revolvers rifled any differently than the service .455s?


.455's will also use the older .476 ctg. Good luck on finding either round at Walmart...

 

[PJGP]

.455's will also use the older .476 ctg.

Sorry Tex, but you are wrong here. Only guns marked 476 will accept this cartridge. The bulbous bullet nose prevents the round from fully entering the chambers. I have checked the various models of .455" Webleys, the Colt and S&W WW I revolvers and also a WW I Spanish OP model. All will take the MkI (long case) .455 and none the .476.

However, there are a number of Webley commercial Service Revolvers that are marked 450/476 and these will naturally take the .476. In these cases the chambers are bored parallel, or pretty much so, with no throats as is usual.

Peter

 

[PJGP]

S&W split the difference with their barrels. Their three models chambered for the .455 Mk II (Webley):

Not so Hondo. The Mk II on the 2nd model HE refers to the gun (ie not a Triple Lock) and not the ammunition. These revolvers will take the Mk I (long case) round.

Peter

 

[Toyman]

To further confuse people Colt produced 960 New Service Target models
with MEDFORD style rifling designed to eliminate black powder fouling.

 

[Hondo44]

Not so Hondo. The Mk II on the 2nd model HE refers to the gun (ie not a Triple Lock) and not the ammunition. These revolvers will take the Mk I (long case) round.

Peter

That's a common misunderstanding.

Smith's "455 MkII HE-2nd Model" revolver was only referred to as the MkII by the British and they stamped it as such on the left side frame.

Smith stamped examples of all three models with 455 MkII only on the barrel, a reference to the cartridge as was their protocol. Also, all three models were chambered to accept the 455 MkI.

Any of the three models can also be found w/o the 455 MkII cartridge marking on the barrel.