I agree with a few comments here. I don't see 'ammo crates'. 7 kind of looks like an 'ammo clip' for a futuristic gun. But for a crate, you might expect someone or something to carry and open them easily, I don't see handles or a way for these to be easily opened to access the ammo. Cool designs for whatever they are...lol!
These are all awesome designs, but they don't look like any sort of ammunition case. Maybe like, an energy weapon recharger? But even that's iffy, I'd have to see some sort of common design language between the weapon and these. Fucking cool looking, either way!