“Also I’m sure she didn’t purchase the ammo for the set.”
That’s literally her job as the armorer. Just like she had to purchase the guns, complete with 4473 forms. She carries a ton of criminal responsibility here.
The guns are provided by companies in California that specialize in guns for movies.
Just as you cannot ship a gun to another person or company in another state, they cannot either. They ship to an FFL in the state where the movie will be made. The armorer as the agent for the legal entity in that state (the production company) goes to the gun store, does a multiple firearm 4473, and leaves with the guns.
The process goes in reverse when they are done.
Basically, this girl was operating as an underground FFL when she let other people go leave with them. And yes, it’s her job to purchase that ammo.
From another article:
He asked attorney for Hannah Gutierrez-Reed, Jason Bowles, “Why were there live rounds on the set in the first place?”
Bowles replied, “That’s the biggest question in the whole case.”
He explained, “There’s no purpose for a live round on this set, zero…There was no reason for there to be live rounds. She didn’t have live rounds. She didn’t purchase any of this ammunition. This ammunition was purchased by other people, production.”
https://ijr.com/attorney-armorer-alec-baldwin-movie-sabotage-set/
She didn’t purchase any of it.