I'm using 455Webley brass in the 2nd Model Smith. The throats are right at .4565 w/groove at .4555. The 455 Webley's are Mark IV's and are all over the place. I don't think they will ever be tack drivers like the Smith is. I also use moonclips in the Webley's 'n 45acp's but would not use same loads you'd use in a 1911. These are loaded down considerably, but are fun to shoot DA. I also was given a big pile of 45 Schofield that I cut down to Webley length. These work very well in 455 Webley that have been cut to accept the moonclips....the rim on this brass is very thick so work pretty good. I've never seen a 455 Webley that has not been cut to accept the 45acp w/moonclips...have you ?? I like using the Webleys for fly fishing. I cut off 303 Brit brass flush with the cylinder face then load up #8 shot using wax GC's down on the powder and also to hold the shot in place. This works extremely well on rattlesnakes, which are plentiful where I like to fish.