Jeff;
As I understand it when these rifles were marked by the gauge system they used plug gages made up in .010" increments. A 118/35 gage was .340" in diameter while the next one up 108/49 was .350". The bbl was marked according to the largest plug which would enter the bore to specified depth. The reason both bore sizes sometimes wer marked with the same gauge was that the 9mm one just barely accepted that size while the 9.3 bore just barely missed accepting the next larger.
You are certainly "Absolutely Correct" in the need to adequately determine actual dimensions of both bore & chamber on these older guns. Excellant & informative post.
