I want to start pretending to be a cop from the 1920s and I just lucked into a Smith and Wesson 581 that was configured for PPC competition. It has a very nice trigger job, a custom slab sided barrel, detachable under-lug, and a classic Aristocrat three position sight.
Slugging the barrel shows that the groove diameter is a tight 0.3564" - 0.3566" and the cylinders all slug to 0.3600". The Ingot to Target Guide says to size bullets to the size of the cylinder throats, but this is a difference of four thousandths of an inch. Because this is such a customized revolver I have to believe this difference was not a mistake.
Any old school PPC-ers know what is going on here?