In my 1903 UMC catalogue the "standard" 10-gauge shell was 2 7/8 inch, but 3- and 3 1/4 inch cases were available at extra cost. Some early 10-gauge breechloaders were chambered for the 2 5/8 inch brass shell. Remember though that in the days L.C. Smith/Hunter Arms Co. was making 10-gauge guns the heaviest available smokeless powder factory-loaded 10-gauge shells were 3 3/4 drams equiv. and 1 1/4 ounce of shot. Those longer shells only ovvered more and better wadding, not a heavier payload. L.C. Smith/Hunter Arms Co. quit making 10-gauge guns well before the Super-Ten came out in the 2 7/8 inch case with its 1 5/8 ounce shot load. Only very late Parker Bros. and NID model Ithacas were made with the Super-Ten in mind. The 3 1/2 inch Magnum-Ten came out in 1932. The only American-made doubles built with that shell in mind were the 887 Ithaca Magnum-Ten NIDs with the longer heavier frame in the 50xxxx serial number range and a very very few, very late, Parker Bros. or Remington Parker doubles.