The NID period Ithaca catalogues begin showing their .410-bores chambered for 3-inch shells and their 16-gauges for 2 3/4 inch shells in 1934. Prior to that 16-gauges were catalogued as chambered for 2 9/16 inch shells. The very first (1926) NID catalogue shows the 20-gauge chambered for 2 1/2 inch shells, but in that the 1925 Flues Ithaca catalogue shows the 20-gauge as 2 3/4 inch I think that may have been an error.
Savage didn't start stating "chambered for 2 3/4 inch shells" in their A.H. Fox catalogues until 1938.
