This is a very complicated subject so I will stick to the Colt stuff.

The 1873 Single action, the Model 1889 and the Colt New Service were chambered in .476 Enfield. They are marked ".476 Cal.". The grooved diameter is .476", an example cartridge has a bullet diameter of .473" with a hollow base and clay plug.

You cannot chamber a .476 cartridge in a 455 chamber.

It is believed that no more than 15 New Service revolvers were chambered in the .476. This is the only one known at this time.



MP Sadly Deceased as of 2/17/2014