[only winchesters]

Hello 4th down: If you truely have a 26in. barrel marked Modified, it's been cut. 26in barrels were only offered with an Imp/Cyl or WS-1 (skeet) choke.(according to my winchester literature) Which would explain the large inside diameter you now have.

Regards Dave

 

[only winchesters]

Hello 4th down: Winchester Proof Steel is heat treated chrome molybelenum steel (alloy) This was delveloped in the late 1920s' and came out in 1931. Prior to that Winchester barrels were Nickle Steel.

Regards Dave