First time I had heard of this:
Steel-Case Ammo Made in USA: Winchester's USA Forged - AllOutdoor.com
<http://www.alloutdoor.com/2016/05/02/steel-case-ammo-made-usa-winchesters-usa-forged/?utm_source=Newsletter&utm_medium=Email&utm_content=2016-05-07&utm_campaign=Weekly+Newsletter>
The "sooty chamber" comment posted (Which is what the author heard from someone, and thus must be subject to the Dean Speir "Gun store guy" rule by my reading at this point) would track with some experience with Russian steel cased ammo if confirmed.
Anyone had experience with this ammo yet?