Webley Mk VI Reloading & Bore Diameter Help

[Patrick Chadwick]

I was expecting something larger as this pistol is supposed to shoot .455 caliber ammo, and most lead bullets for this unit are supposed to be about .453-.454.

Back to basics: it is a REVOLVER not a PISTOL.
The difference is not just a matter of words. When a revolver is fired, the inertia of the bullet means that it first tends to obturate (bump up) to fit the front of the chamber in the cylinder, then it is rammed into the forcing cone and swaged down, then it is finally forced into the rifling. Quite a lot of stress in this process, so the first consideration, especially as this is a design going back to the black powder era, is to be kind to the mechanism and NOT feed it with modern jacketed bullets! As pistols do not exhibit this bump up/swage down effect, they can use much closer-fitting, harder bullets.

The 455 designation is also a hang-over from the 19th century. For all practical purposes the Webley Mk VI is a .45 revolver. 452-453 lead bullets fly very satisfactorily. Once again, this is all happening at BP velocities, so a BH of 15 is sufficient and also permits an adequate bump-up effect. The original bullet was a 255 (or was that 265) gn round-nose with a hollow base (which aids the bumping up).

It is a pity that the cylinder has been shortened. This was done post WW1 to enable the use of 45 ACP ammo. However, most modern .45ACP is going to be unsuitable (too hotly loaded, bullets too hard). Using moon clips is also a PITA, if you can even find them. That is why 45 Auto Rim was invented, and those are the cases which you should use, and forget the moon clips.

I don't know if you will be able to find such ammo at an acceptable price, so I think you are going to have to get used to the idea of loading your own ammo if you want shooting satisfaction from a Webley.