David, always trust the manufacturer's UPC code which confirm these are "Steel Cased", Copper Jacketed, Lead Cored, Boxer Primed ammunition.

David, These rounds are "steel cased" with a brass wash. I have a case sitting here I have to use at the farm. Can't use them at the range.

its a steel case see**** Features and Specifications:
Manufacturer Number: WIN9SV
Caliber: 9mm Luger
Bullet Type: Full Metal Jacket (FMJ)
Bullet Weight: 115 Grains
Rounds: 50 Rounds per Box
Muzzle Velocity: 1190 fps
Muzzle Energy: 362 ft/lbs
Jacket: Copper Primer; Boxer
Core Material: Lead
********Casing: Steel
Non-Corrosive
Usage: Target, Plinking

David all of the "Forged" ammo is steel case. The bullets are brass jacketed and that is likely how the case description was automatically filled in to say Brass by the web site.