I assume that very early 20 ga. Ithaca guns had 2 1/2" chambers. I believe that all NID's had 2 3/4". Anyone know when 2 3/4" became the standard 20. ga chambering? I'd guess sometime during the production of the Flues. Looked in Walt's book, but if it's in there, I can't find it.
ITHACA CHAMBERS -- The last Flues period catalogue (1925) states -- "Unless otherwise ordered Ithaca 28 Gauge and 20 Gauge guns are chambered for the standard 2 1/2 inch shell, 16 Gauge and 12 Gauge for the standard 2 3/4 inch shell and 10 Gauge for the standard 2 7/8 inch shell. Longer chambers are furnished if ordered on new guns without extra charge, but it should be remembered that shells of standard length do not give quite as good results in chambers which are longer than the shells and it should be remembered that extra long shells are more expensive and it is much harder to find a dealer who carries extra long shells in stock." I find that 2 3/4 inch pretty strange in the 16-gauge, because 2 9/16 was the standard 16-gauge shell until WW-II!?! None of my earlier Flues period catalogues mention chamber lengths.
Beginning with the first NID catalogue in 1926 they state -- "Unless otherwise ordered Ithaca .410 Cal. and 20 Gauge guns are chambered for the standard 2 1/2 inch shell, 16 Gauge for 2 9/16 inch, 12 Gauge for 2 3/4 inch and 10 Gauge for the standard 2 7/8 inch shell." The 28 gauge doesn't appear in NID period catalogues until 1932 though they did make some. Beginning with the 1927 catalogue the sentence is changed to -- "Unless otherwise ordered Ithaca .410 Cal. guns are chambered for the standard 2 1/2 inch shell, 16 Gauge for 2 9/16 inch, 20 and 12 Gauge for 2 3/4 inch and 10 Gauge for the standard 2 7/8 inch shell." Ithaca catalogues for 1926, 1927, 1927-1928, 1928, 1929, 1930, 1931-1932, 1932, No. 50F, and No. 51S, all list 16-gauge as 2 9/16-inch chambers. Beginning with the 1932 catalogue the 28-gauge with 2 7/8 inch chamber is added to the list and it also introduces the 3 1/2 inch Magnum Ten Gauge. By Ithaca catalogue No. 51F the 16-gauge is finally listed with 2 3/4-inch chambers and the 410-bore with 3-inch chambers. I believe the catalogues No. 51 equate to 1934.
Yep! There it is, right on page 352. Thank you both very much.