The real problem with 16s is loading the shells lighter to shoot clay targets, like skeet for practice. Talk to other guys with Flues 16s over on 16ga. com. Ask about shooting factory 1 oz loads in the gun. My 16ga Flues was basically a backup gun to a Sauer made between the wars which was about as tough as a tank. Ithaca stopped making the Flues in 1926 when they brought out the NID (New Ithaca Double). The change was as a result of the appearance of the first of the truly modern shotshells which delivered more velocity and higher pressures. (The Super X was the first.) Ithaca more or less previewed some of the NID changes in the Nitro Special, which they introduced in 1921. I did shoot modern pheasant loads in my 16ga Flues without any issues, but I'm not sure I'd do that again.
If you're going to focus on Ithaca sxs, then you really should pick up Walter Snyder's Ithaca book: "The Ithaca Gun Company, From the Beginning" (2nd edition). That's basically the Ithaca Bible.
Good luck.
