Addendum
The Sporting Arms and Ammunition Manufacturers’ Institute (SAAMI) accepted the Winchester .350 Legend as a new cartridge and chamber standard in early 2019, but there is still some confusion. Here’s a direct link to the .350 Legend and technical specs and drawings, courtesy of SAAMI.
The cartridge uses a modified, .223 Rem. shell case with a 1.71-inch length and a bullet diameter of .357 inch.
