W9MM over 2020 9mm Luger

Personally have never seen this head stamp. A friend purchased some ammo asked if I knew who was the manufacturer of the brass. I guess Winchester but it’s only a guess. Looked at the lists but didn’t see any that where formatted like that. How far off am I? The ammo was commercial reloads.

zzzzz

I have a fired case I got from another IAA member. I don’t know who made it.

Lew

I have some of this. Was included in a gun I got today. Never seen it before.

James - do you perchance have a picture of the box label for those rounds. I have never seen this headstamp and perhaps a picture of the box label would be a clue to finding one.

John Moss