I beg your pardon eightbore but I knew that some Winchesters were stamped 2 9/16. I didn't mean only the Model 21s. That's why I said what I did. I believe when it was back in the nickel steel era. And I know when Mike (don't remember his last name) was on here we had a conversation and someone said their 21 was stamped 2 9/16. Sorry if you missed that. And I didn't say that I had seen any marked 2 1/2. You need to read the posts a little better.