With all due respect to dfw (who has forgotten more about revolvers than I know), it is possible to chamfer more extensively (at 45°) if you are using auto pistol cartridges (.45ACP, 9x19, .40S&W). They are designed to work with less chamber support than revolver cartridges. This is especially true with a low pressure cartridge like the .45 ACP. I have seen chamfers so big the chambers looked like little funnels, some 0.030" or more. And it's very fast.


Buck