Is that really true? I guess it depends what you’re looking for. If you just want a thing that reliably goes ‘bang’ once, then I’m pretty sure you could make it completely out of plastic just fine. If you want something that is reliable over hundreds or thousands of rounds, yeah, you’re probably gonna need some metal.
Oh, wait; the ammo. Hmm, I reckon with a bit of time and effort you could make a metal-less rounds, maybe leveraging the caseless ammo concept.
Even if they were completely plastic, they’d still be detectable.
