If it's to decorate a bandolier or guitar strap, the red plastic ones won't work.
You need to have someone take real bullets and real shell cases and make you up some Inert Rounds.
Which you'll have to explain to every cop you run across. All they see is Real Bullets, and you'll have to show them the empty primer pockets with a little slug of Silicone Seal filling the hole...
That, or search jewelry supply houses - I'm sure someone mass produces them. While they won't stand up to close-up scrutiny because they're totally fake, they'll be fine on a stage viewed from 20+ feet away.