I don’t know, I think there’s a way to do it without the physical guns. I’m reminded of Doyle’s “Sweeney Todd,” where nobody’s throat was shown being slit. But the buckets of blood were enough of a statement to get the point across, in an equally disturbing way.
If you’re doing a straightforward production of “Assassins” it would probably be weird without actual guns. I feel like Doyle’s production will be anything but straightforward.