Inert projectiles and cartridge are legal to own here in Utah - you might want to check your state and local laws though!
The 'BRASS' isn't brass, its an alloy or aluminum.
I have a couple 40mm Bofors cartridge cases that are BRASS and 105mm BRASS cases PM me if you are interested!?
Also, check GUNBROKER. Key words 30mm; INERT; CASE; or BRASS.
~Will