[A5guy]

Winchester experimented with the 14ga and made some aluminum cased 14ga ammo for their Model 59 14ga guns. Also, there was at least 4 Model 21 SxS Winchesters made but they were kept under wraps.

 

[A5guy]

The 1897 Sears & Roebuck catalog lists all brass 14 gauge unloaded cases. They were made by U.M.C. Company, a predecessor to Remington. They were 2 3/8 inch and used a #2 primer. These cost $1.17 for 25.

They also offered paper pin fire 14 ga shells at $.65 for 100. I believe that these were 2 1/2 inch shells.