I do not have a Galazan chamber gage so do not know what diameter they are made to. As to the "Old" guns, be aware that SAAMI specs did not exist when most of them were built. Present specs call for a minimum chamber diameter at the juncture with forcing cone of .798". MANY old chambers, even of 2 3/4" length may run from .001"-.003" smaller than this. "IF" that chamber gage is made to the .798" diameter it will show the chamber being from 3/16"-Ľ" short for every 001" it is undersized. This undersize does not present a hazard & does not require either short shells or a chamber lengthening.
I check the length of my "Old" guns with a 6" flexible machinist scale. In fact, one of the "General" brand you can pick up at a home improvement store for about 3 bucks will work as well for this use as a Starrett or Brown & Sharpe.
I hold the barrel up toward a light, such as an open window, not concentrated & view the shadow line where the cone starts. The scale can be slid in touching the chamber wall until the corner just touches the shadow line. Hold it right there & bring the barrel down & read scale. Actually much more accurate than a misfitting chamber gage.
