I'm talking about gages made to specs. Problem here is so many of the guns we deal with here were made prior to those specs. With a body taper of .005" per inch a mere .001" too small chamber will stop a gage short by .200" or a 2 3/4" chamber will show up as approximately 2 9/16. That .797 JDW mentioned in the L C Smith specs is neither SAAMI nor CIP specs, but simply SS (Smith Specs). I made a very nice set of gages 12, 16 & 20 to SAAMI spec for minimum chamber dia at forward end. I very quickly found that dealing with pre WWI guns I could get a much more accurate measurement of actual chamber length with my 6" scale than with these precision turned gages. This is a case where one size just won't fit all.
"IF" one wants to get arrogant as to the ""ONLY"" way to do it then what ois really needed is some cerro-safe casting alloy & a shadow-graph to read the cast. With this set up you can find absolutely anythibg about the chamber, bore, cone etc you would ever want to know.
My friend I spent 35 years in a machine shop measuring everything imaginable & I can assure you a set of those gages is not the "Only" way to accurarely measure chamber depths, in fact they are not even the "Best" way, "Unless" you individually build a gage to fit for each & every chamber needed to be measured. But by the time you figure that out you have no further need for the gage.
But Hey, if you want to rechamber your guns from 2 3/4" to 2 3/4" just because one happens to be .001-.002" under the gage size that's fine with me. As to my guns "IF THEY AIN'T Broke I DON'T FIXEM" so I'll just keep right on using my little $3.00 scale.
