Wasn't going to respond to this thread, 'cause I'll be here for hours.... Instead I'll try to be brief.
Suffice to say that a few of us here in Darwin shoot Webley revolvers often at our Collector shoots, and prior to Australia's post-Monash restriction on .45 calibre for pistol club use, I regularly shot the full 90-round Service Pistol match with a Mark VI, occasionally placing! Went through many thousands of WestCast pills, hollow base with the green coating, loaded in Mountain & Sowden brass. Even made my own cannelure tool to improve the crimp for better accuracy. And yes, the trigger required utmost concentration...!
My favourite .455 however is the Mark II, rounded birds-head fits better in my hand and love that over-sized hammer shroud!
Also have S&W Hand Ejector and a couple of Colt New Service in .455 as well as the other Marks, love them all but the Webley "manstoppers" definitely have more historical appeal, probably due to our British Colonial origins.