http://www.doublegunshop.com/forums/ubbthreads.php?ubb=showflat&Number=401138 with Bro. Walter's Ithaca Skeet engineering drawing
Capt. E.C. Crossman Skeet Gun Patterns in August 1936
Hunting & Fishing He formerly believedthe proper boring for a double 12 Skeet gun consisted of an improved cylinder right for Station 8 and incomers, and a much tighter tube on the left for the outgoers and all singles except Station 8; such a boring as improved modified or the famous
Winchester No. 2 Skeet, or in barrel measurements, around .015.
But now feels the Winchester No. 2 Skeet boring is too tight and improved cylinder or No. 1 boring is both barrels seems about the right dope.
He went on to criticize the Cutts spreader tube on single barrel guns for skeet, but did not define the tube diameter.
He mentioned a Fox with .011 left and a Model 32 Remington bored for skeet lower barrel .012.
Improved cylinder is the greatest degree to which a plain barrel should be opened, this being not less than .004.
The finest example of this at present is the Winchester No. 1 Skeet boring, which has about .004 choke at a point 3 from the muzzle. The muzzle section then becomes largeruntil finally the barrel at the muzzle is about 0.750 instead of the normal 0.730 of the 12. This is a relieved muzzle or bell muzzle, originated by Ithaca years ago.
