In 1897, Webley introduced the 455 Webley Mark-II. This followed the longer Mark-I that was introduced in 1891. Other than length, the cases are identical; when properly adjusted the same dies should work for either version. These used conventional inside-lubricated bullets of 0.455-inch diameter and most loads generated about 300 foot-pounds of energy when loaded to full specification pressure, which was modest at 13,000 psi. The variety of Military and civilian load options through the decades until the 455 became generally obsolete, about 1970, is positively mind-boggling. It was evidently the first cartridge ever commercially loaded with a hollow-point bullet. Those loads were so effective the design was explicitly called-out and outlawed for use in war by signers of The Hague Convention of 1899. This alone should give the 455 a place in the annals of great inventions pushing the art of self-defense forward. The 455 comes close to duplicating modern 45 Colt factory-load ballistics but owing to the shorter case and overall cartridge length, it can be loaded with propellant type and charge combinations that work well and come far closer to filling the case. As such, it has a theoretical advantage in ballistic uniformity because the powder-position-effect will be significantly less; in that regard, it resembles the 45 Automatic and can give excellent accuracy results when used in a quality revolver in good condition. The complicated mechanism of the Webley-Fosbery self-cocking revolver did not lend itself to extreme accuracy. The top-break Webley revolvers, as with the top-break S&W revolvers tend to lose accuracy with use because of rapid wear in the hinge connecting the barrel and cylinder assembly with the frame. Regardless, examples of these guns in good condition have proven entirely adequate for self-defense and battlefield use. As with any revolver round, best practice is to apply a roll-crimp after seating the bullet. A roll-crimp eases loading of rounds into the cylinder and can help limit bullet pull under recoil if only modestly. I cannot too-strongly recommend getting a second seating-and-crimping die so you can have one adjusted to only seat the bullet and the second adjusted to only crimp the case mouth. Generally, attempting to do both operations in one step is a recipe for damaged and destroyed cases. This is merely a shortened version of the case used for the, circa 1873, 45 Colt.