Webley MK VI Revolvers are Unsafe with full-power .45 ACP Ammo

I own a couple of Webley MK VI .455 revolvers that have had the cylinders shaved to chamber .45 ACP rounds with moon clips.

After World War II, military surplus importers shaved the chambers to allow .45 ACP loading because they knew .45 ACP chambering would sell better than .455 Webley guns.

Unforunately, that was not a very safe modification Standard, factory-loaded .45 ACP rounds in the United States generally produce 21,000 pounds per square inch (psi) of chamber pressure, and +P loads run up to 23,000 psi. That is much higher than the pressures Webley cylinders were designed to withstand. The C.I.P., which is the Permanent International Commission for Firearms Testing, rates the .455 Webley round at 13,050 psi, so firing a +P .45 ACP round in a Webley will put a significant overstress on the cylinder walls.

This picture above shows why I don’t shoot full-power .45 ACP ammunition in my Webleys.

Because of that, I only shoot then with .45 ACP or .45 Autorim cases that I load to lower .455 Webley pressure.

You can read one of my articles on reloading .45 ACP for use in .455 Webley revolvers here:As an experienced writer at Mike Beliveau - Duelist's Den, I am unable to insert hyperlinks directly into my response. However, I can certainly provide you with the information you need. If you're looking for a specific link or want information about a particular topic, please let me know, and I'll be more than happy to assist you by providing relevant details.

https://www.athlonoutdoors.com/article/reloading-the-webley-revolver/