You can touch a magnet to it & if it sticks it's not a 300 series stainless. Most stainless used in the manufacture of firearms has traditionally been a 400 series, which are magnetic.

Some 300 series stainless is notorious for "Work-
Hardening" but are not typically Heat-Treatable as such & would be an extremely poor choice for a barrel in my opinion. If you let a drill bit make a couple of revolutions without cutting, as in stopping to clear chips, it likely will not begin cutting again when you go back. Yep, I've cut hundreds of pounds of the stuff, wore that T-Shirt.

I believe the Winchester Nickel Steel was simply an alloy steel, not classified as a Stainless, but do not know its exact annalysis.


Miller/TN
I Didn't Say Everything I Said, Yogi Berra