My 16ga Lefever I mentioned with the 3" chambers would fall within a 1907-1915 range. It carries a 1907 patent date & shows no sign of being an Ithaca assembled gun. I come much nearer believing this gun was so ordered that way when new than that it was re-chambered in the '30's era you mention re the model 21.
Some time in the 1970's I was at a gunshop when a gentleman brought in an empty fired hull to show. He had been hunting in the mountains of Franklin Co TN & found this hull. It was a Remington SP plastic 3" 16ga hull. Load marking was still readable on the side & it stated 3DE-1˝oz-#7˝ shot. Never saw any of these come on the market anywhere, anytime, but apparently Remington did experiment with them. In my opinion it's fortunate they didn't catch hold. If you need an ounce & a half of shot use a 12.
