What is Winchester proof steel?

Answer 1

Introduced around 1940, Winchester Proof Steel is the alloy used by Winchester to manufacture it's firearms. It replaced nickel steel, used in the early production Winchester 94's to withstand the power of the first 'main stream' smokeless powder rifle cartridge - the .30 WCF, now known as the .30-30. Note, however, that the 94 Winchester was intoduced in .30 WCF a year after the production of blackpowder 94s. Winchester Proof is stronger than nickel steel, and holds blueing better. The nickel in nickel steel made blueing flake off of recievers and barrels of Winchester rifles over long periods of time.

Winchester introduced Proof Steel in 1931, and began using it for the Model 94 in April of 1932. "Proof Steel" is a chrome-moly alloy.