Can someone tell us what kind of metal the following actions are made from. Are any chromemolly?
Win M54
Win M70Pre64 (both pre and post war models)
Brno 21,22,ZG47,Zkw465.

you can have a metallurgical analysis done.

Unless one worked for these companies and had direct knowlege of their materials they are guessing.....possibly someone had an analysis done.....

This is my guess....the only ones you mention made from 4140 chromemoly is the post 64 winchester. I assure you....that's a guess.

If someone knows I'd like to know how the information was gleaned.

Firearms manufacturers are pretty tight lipped about the exact steels they use...and they don’t buy their steel at the local supply store. Most of them have long standing contracts with the major steel producers and each will have their own “recipe†for the steel they purchase.

4140 steel can have varying amounts of Chromium and Molybdenum in it depending upon what its intended use is. Chromium adds wear resistance and toughness to the steel and Molybdenum adds heat resistance and hardenability.

Merely saying that something is 4140 Chromemoly doesn’t really tell you all that much in a true metallurgical sense.

4140 is 4140. There is an ANSI spec for it, which does have a range, but it is relatively small. The big thing with 4140 is it's heat treating state. The reason it is so widely used is the fact that it is heat treatable, and its properties vary widely with the specific treatment.