Shooting the Webley Mk VI
.45 Auto Rim Revolver

The Webley Mk VI Revolver

The .455 Webley Mark VI was the last of the large frame, big bore Webley revolvers. The series had originated in 1887 with the introduction of the Mark I revolver, itself evolved from the highly successful "Bulldog" pocket revolvers chambered for the earlier .450 Adams cartridge. The Mark VI, adopted in 1915 for the Great War (aka the First World War), was the largest of the .455 Webleys, having the previous Mark V's heavier frame and cylinder to handle the Mark II .455 Cordite cartridge and a longer six inch barrel. It also had a redesigned square butted grip, a departure from the classic bird's head grip found on all the previous models. Although a large frame revolver, it is surprisingly light.

Following the First World War and the decision to replace the .455 with a lighter pistol in .38 caliber, it became the inspiration for the Webley Mk IV revolver chambered in .38 Smith & Wesson (aka the .38/200 S&W for its 200 grain bullet load), which was first rejected by the Royal Small Arms Factory and then shamelessly copied as the Enfield No. 2, Mark I (the Mark IV was later produced by Webley in 1942 to meet wartime demand). Although officially superceded by the .38 caliber Enfield No. 2 revolver in 1932, the big .455 Webley Mk VI remained in military service through World War II and briefly afterward.

Webley Mk VI revolver and Fairbairn-Sykes commando dagger

The Webley Mark VI is chambered for the .455 Webley cartridge (aka .455 Eley and .455 Colt), originally charged with 18 grains of blackpowder and a 265 grain round nosed, hollow base bullet, delivering a muzzle velocity of 750 fps (per Eley Brothers 1910 - 1911 catalog). This puts it on a par with American contemporaries such as the .44 Smith & Wesson Russian and .45 Schofield. The .455 Webley had the same cartridge case as the earlier .476 Eley service cartridge, but the latter had used a heel based bullet that permitted a larger diameter that was flush with the outer diameter of the case (i.e., similar to the modern .22 Long Rifle rimfire). The Mark I blackpowder loading was eventually superceded by the Mark II Cordite loading which, possibly out of concern about the interchangeability with the older blackpowder .455 and .476 revolvers in which it might be used, was held to a lower performance standard than the Mark I load, achieving as little as 600 fps in later loadings. This may also have been partly attributable to the shortened Mk II case (0.770 inches versus 0.890 inches), which change was allegedly made to achieve more consistent performance with the smokeless propellant. There was briefly a very interesting Mk III Manstopper load consisting of a 220 grain hollow-pointed wadcutter at higher velocity, but this quickly fell from grace due to the absurd Hague Convention of 1899 and was superceded by a Mk IV 220 grain flat nosed wadcutter bullet.

Following World War II and the withdrawal of the Webley Mk VI from British military service, thousands of these revolvers were imported to the US. Most were converted to fire the .45 Auto Colt (.45 ACP) cartridge in a very ill advised attempt to make the weapons more appealing to American shooters who could more easily obtain military ball ammunition. The Webley Mk VI cylinders were turned on a lathe to shave off enough metal on the rear face to permit the necessary thickness for the rimless .45 ACP cartridges when snapped into half-moon clips, as had be used with the Model 1917 Smith & Wesson and Colt revolvers of the same vintage as the Webley. However, these pistols were designed for the higher pressure of the .45 ACP cartridge and the Webley was not.

Like most, my Webley is one of these converted pistols. This webpage is the result of the challenge of recreating authentic, original performance loads for the Webley Mk VI revolver that are safe to use, accurate and effective.

Load Development and Shooting

Load Development

The Commission Internationale Permanente pour l'Epreuve des Armes 'a Feu Portatives (CIP) rates the .455 Webley Mark II cartridge with a maximum average pressure (MAP) of 900 bar, which is 13,050 psi. At face value, this compares well to the marking stamped on the barrel of my pistol that indicates 6 tons per square inch, or (nominally) 13,440 psi. However, this 6 tons psi is actually copper units of pressure or CUP, not true psi as with the CIP value. Furthermore, it is probably base or axial copper crusher measurement per British Proof House practice, as opposed to radial or side measurement. Using the conversion of British Proof House tons per square inch in true pressure (derived from CIP data) gives 1050 bars and 15,230 psi for 6 tons psi. Since 1050 bars is squarely between the CIP rating for the .45 Colt and .45 Smith & Wesson Schofield, and consistent with SAAMI specs, I feel confident this is still a safe upper limit. I believe the 900 bar MAP imposed by the CIP was made in deference to the older blackpowder revolvers.

The .45 Auto Rim is rated by CIP to 1200 bar, or 17,400 psi, while the standard .45 Auto Colt rates 1300 bar, or 18,850 psi. However, US manufactured .45 ACP ammunition is typically loaded to a much higher level than this; SAAMI permits 21,000 psi for standard loads and 23,000 psi for +P loads. What this means is that if standard .45 ACP loads are fired in a Webley Mk VI revolver they greatly exceed the proof test pressures, being 38% over the MAP, and are potentially dangerous. Most unreformed .45 ACP users in the Webley Mk VI note that a "steady diet" of such loads will "loosen things up." Read that as, "will produce yielding in the metal of the cylinder and frame with every shot fired." Steel can be a very forgiving material, but not always. In some cases, the cylinders have been catastrophically destroyed, with injuries to the shooter.

All of the foregoing is academic, meant merely to inform and to caution. My approach did not involve trying to measure pressure. The solution is easily realized: set a goal of duplicating the original performance (650 to 750 fps) with a relatively slow burning powder (by pistol standards, of course). If you don't try to push beyond the original blackpowder ballistics, you will not have a problem. Its worth noting in this regard that the case capacity of the .45 Auto Rim cartridge is greater than that of the .455 Webley Mk II case (even subtracting the extra thickness of the former's rim), which means that performance duplicative of the original loads can be achieved at lower pressures (it is very similar to, only slightly longer than, the .455 Webley Mk I case).

Cartridge Cases

Since this revolver has been converted to fire .45 Auto Colt, I first obtained a quantity of these cases and several full-moon clips, as well as a tool for extracting the fired cases from the clips (which is a lot harder to do than you might imagine). Having done that though I also decided that I wanted to get some ordinary .45 Auto Rim cases that would not require me to hassle with the moon clips. Both of these are readily available (far more so than .455 Webley).

Incidentally, although I bought Lee .455 Webley dies, you can use .45 ACP, .45 Auto Rim or probably even .45 Colt dies, as long as you adjust the insertion depth on the sizing die. The nice thing about .455 Webley dies is that they allow for the correct .455 caliber bullet diameter. The others assume a .452 caliber bullet.

A comparison of the .45 Auto Rim and .45 Auto Colt Pistol cases

Bullets

Buffalo Arms makes an exact duplicate of the original bullet for this cartridge, pre-lubricated with SPG. It has an elongated round nose, about the farthest thing from what is wanted for lethality, unless the alloy is very soft. Buffalo Arms casts these of 20-1 alloy, which is fairly soft (BHN 10 - 12), but not soft enough to expand much at these velocities. It also features a hollow base, as did many bullets of the era, which facilitates a tight gas seal and covers many sins in manufacturing dimensional tolerances.

A better thumper load is made with a Keith style semi-wadcutter (SWC). As it happens, Beartooth Bullets (which, circa 2023, appears to be defunct) makes a heavyweight bullet in this style that is the proper 265 grains and can be ordered sized to the proper .455, .4555 or .456 caliber. It can even be ordered lubed with SPG for low pressure, low velocity loads, as I specified. A wide-nosed (meplat of .350 inch) Keith style SWC bullet has no need of expansion to be effective, but were it cast in a soft alloy (the Beartooth bullets are not) it would be more apt to expand than the long tapering round nosed original design. Montana Bullet Works makes a 250 grain LBT-style wadcutter with a .415 caliber meplat that can be had sized to .455 caliber and I plan to try these out some time in the future.

Jacketed bullets are not recommended in this caliber because they will be too small in diameter at .452 caliber for best accuracy and the jacket would typically preclude any expansion even with a hollowpoint. There may be some exceptions to this rule, however, such as the Speer 250 grain Gold Dot JHP, which is designed to expand at original .45 Colt velocities.

Buffalo Arms .455-265 grain Webley RNHB and Beartooth Bullets .456-265 grain Keith SWC

Propellant

There are numerous propellants that might be used for this purpose. Anything that works well in the .45 ACP would be a good start. In order to be kind to the older Webley action, the best choice would be one of the slower medium burn rate pistol powders. I would definitely not recommend attempting to duplicate the upper end of original performance with the faster burning propellants. Among the good choices would be Hodgdon Universal, Longshot or HS-6, IMR-4756, Blue or Hi-Skor 800X, Alliant Unique, Blue Dot, Power Pistol and Herco, Ramshot True Blue or Accurate No. 5 or No. 7.

In my case, I happened to have Winchester 540 on hand from previous load work. Its a good medium speed pistol powder, but in modest capacity cases like this it qualifies as a slow burning propellant, which means that it will deliver the highest velocity with the lowest pressure. Winchester 540 is no longer marketed under the Winchester brand, but it was manufactured by Hodgdon for Winchester and they still make it under the name HS-6. They are the same powder (indeed many propellants sold today are marketed under different names).

For comparison to the original blackpowder load of 18 grains, I loaded a 75% ratio (by weight) charge of 13.5 grains of Hodgdon Triple-Seven (H-777) FFg. Now, FFg double-fine grade is not a pistol propellant, it is a rifle propellant. Triple fine grade, FFFg, is pistol propellant, but I did not have any at the time. Nevertheless, the FFg produced almost 700 fps on a moderately cool day (55 F), a bit shy of the book velocity, but broadly consistent with original blackpowder performance. I intend to revisit the original blackpowder performance in future using Hodgdon Triple-7 FFFg and also GOEX Olde Eynsford FFFg and will report my findings. I expect the FFFg loads to deliver velocities between 725 to 750 fps.

Disclaimer

Warning: Use this load data at your own risk. No liability is assumed for the use of this data in any other firearm. It appeared to be safe in the test revolver, but was not subjected to pressure testing. Exercise safe reloading practices. Starting loads should always be reduced by 10% from the maximum load.

Loaded .45 Auto Rim cartridges with .455-265 grain Webley RNHB and Beartooth Bullets .456-265 grain Keith SWC

The Keith SWC style bullet is in theory a more practical defense load, but I have to say that the original Webley RN looks awesome! It also shoots very well in this old and rather loose revolver, no doubt due to the soft lead alloy and the hollow base design.