I purchased in an on-line auction, and received today what I believe to be a .455 Mark II hand Ejector 2nd model that has been modified. I didn't spend a lot on it, so it's a keeper (for a shooter).

N Frame with Canadian(?) "arrow", Crown over 66 over E, and "11" on left side of frame and "crown over BV and crossed pennants on the left front side of the frame.

Multiple BNPs on barrel and by each cylinder. Barrel (left side) is marked "Smith & Wesson .455" with the second 5 x'ed out and AR added.

The butt has a plugged lanyard hole and the S/N 63055 Barrel marked B 63055.

It has been refinished - with fairly crummy preparation in some places, but nice bluing. The trigger was blued, but not the hammer. It is absolutely vault tight.

The cylinder has not been shaved. There is no serial number on it. I read in SCSW that many were converted to .45 AR, and this seems to be a textbook example of that. It looks like it was not shot after conversion.

A 45 ACP shell drops in, but the ejector will not eject or even come close to catching. I am hopeful that I can use moon clips successfully.

It has replacement grips, but I'm not concerned with authenticity after the refinish/conversion.

That's a great shooter you picked up! Congrats.

When modified for AR it will definitely allow moon clips. Since there's no serial # on cyl, not even a different #, it had to be shaved. Whe the cylinder is opened, will it move fore and aft? Another sign of a shaved cyl. if the cyl stop lug hasn't been turned slightly to make up for shaving the cyl. If it moves the lug can be turned to adjust for it.

NOTE: 455 Mk II ammo (also referenced as 455 Webley) is in the 14,000 pressure range and the 45 ACP in the 19,000 range to insure it would cycle the 1911 slide reliably. Your cylinder was not heat treated as were the Model 1917 Smith and Colts. Hence a precaution against using full load ACP, especially +P loadings.

If you reload 45 ACP, just keep them in the 45 AR pressure range.
However the 45 AR (Auto Rim) was designed for revolvers and is in the same 14,000 low pressure range as 455 ammo, thus perfectly safe. But very hard to come by!

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Jim
S&WCA #819

Jim - thanks for the insight. I have bought all of the components and equipment to start reloading, but have not started yet. I will remember your recommendation.

Jim

SAAMI states the pressures for 45 ACP are acceptable up to 21,000 psi, while the 455 was under 14,000 psi, so pressure differential is actually over 30%, which is way too much for me to consider firing even any factory 45 ACP in a 455 revolver. There was a post in the British Militaria Forum a few years ago on this subject that I feel contains some solid information and advise.

1. The operating pressure for the Mark VI Webley revolver (the last, and strongest, of the .455 Webley service revolvers) as well as other 455 military revolvers of the era was a maximum of 13,200PSI (i.e. six 'long tons' of 2200 lbs).

2. The standard operating pressure generated by milspec and full factory loads of .45 ACP ball ammunition is over 19,000PSI. SAAMI states higher, 21,000PSI as a standard loading.

3. The pressure of .45 ACP milspec and standard factory loads exceeds the proof load for the Mark VI Webley revolver and other military revolvers used in WWI.

4. You will likely have been told (or have read) that it is fine to shoot "factory" or "GI Spec" .45 ACP (or .45 Auto Rim) cartridges in your altered .455 revolver, and you may well already have put many such rounds through your revolver without mishap.

Please be aware that in the view of many, IT IS NOT SAFE TO FIRE SUCH ROUNDS.

The photos are of a Webley and not a S&W, but who wants to take the chance. Hand load you 45 ACP to something under 14,000psi to be safe.

Attached Images

	455 Cylinder.jpg (12.5 KB, 67 views)
	45 ACP casings.jpg (15.0 KB, 64 views)

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Gary
SWCA 2515

That looks like a standard British Broad Arrow to me. The Canadian version has the same mark within a capital C. This column of markings indicates that it was accepted into British military service by inspector number 66 at the Royal Small Arms Factory at Enfield Lock.

The "11" should be a Roman Numeral 2 (II), indicating that this is the second model S&W approved for British service, the first being the renowned "Triple Lock".

I believe you can still find .45 Auto Rim cases for sale.

I've been looking for one like yours, except converted to .45 Colt. IIRC, the max pressure of the .45 Colt is 14,000 psi.

Edited to add:
Look carefully at the "66" to be sure it isn't "G6". I don't want to look it up right now, but I seem to recall that the inspectors were assigned IDs in the form of "Letter Number".

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You're shy a few manners.

If your looking for an original unaltered (Scarce) .455 Mark II cylinder - I have one.

45 AR was not loaded to ACP specs, not over 14,000, and is safe to shoot.

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Jim
S&WCA #819

Was over at the starline brass website and they list new 45 auto rim cases as being in stock. Frank

I find references for "standard" 45 Auto Rim being offered in many bullet weights up to 230 grains and speeds up to 1100 fps. I also find references to pressures from various factory loads at 17,000psi to 19,000psi.

As stated in the information above, there are many of these converted 455s that probably shot lots of both auto loads without incident. Even those converted to 45 Colt can end up shooting factory ammo that exceeds even 45 ACP pressures. That does not convince me to do the same, when a reloader can hand load to much safer pressures and punch the same diameter holes through a piece of paper without worries. My opinion is that pre-heat treated cylinders were simply not designed for the higher pressures from either 45 ACP or 45 Auto Rim.

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Gary
SWCA 2515