Back in the early 1920s, when Western Cartridge Co. introduced the use of progressive burning smokeless powder and high velocity shotshells with the introduction of their Super-X loads, their new 20-gauge 1 ounce load was put up in their 2 3/4 inch FIELD shell. Most of our other North American ammunition companies followed and put their 1 ounce progressive burning powder 20-gauge loads up in a 2 3/4 inch case, Remington Nitro Express, Peters High Velocity, etc. Winchester, possibly because they had many customers out there with their 20-gauge Model 12s made for 2 1/2 inch shells offered a choice --
These are both roll crimp shells. The pie crimp was introduced by our North American manufacturers in the 1938/9 time frame on their Trap and Skeet loads, but didn't begin appearing on hunting loads until after WW-II.
Threaded Mode