No, I measure everything I get back from the machine shop before I assemble the engines, so everything has to be measured accurately. Some tolerances need to be less than 0.001'' and are critical, especially when customers are paying 15 to 20 thousand or more for a rebuilt engine. Been doing it for close to 45 years, and the so call best machine shops in town, for the most part, are not.wcwhitey, amen. Somewhere a customer service rep's head exploded over some things consumers worry about. Appreciate the OP's ability to measure things, but do wonder if he pulls the head on his car, making sure the pistons are in spec for the bore.
Sigh.
Moon
VTI has cylinders but they can not measure them, but will allow me to return them if I don't like the throat sizes. Depending when they were manufactured they may all be 0.366''.I think I would just try a new cyl from VTI.
I just got a "used but not shot" Pietta Frontier from Cimarron in 45C. The hand channel was way out of spec and allowed throw-by rather easily . . . which meant the cyl had some "oops marks" on it. I ordered a SS 45C cyl for it as well as a blued 45acp cyl. It shoots very nicely with either cyl. and runs like a fool!!! Lol
Mike
Later I searched again and the MMC was on the SAAMI drawing of the .357 chamber. Also I read the wrong column in the ISO tolerance specs. It was even larger than I thought at plus or minus 0.2mm (plus or minus 0.008 inches) !