Videomaker – Learn video production and editing, camera reviews › Forums › General › Video and Film Discussion › DIY futuristic prop gun building or other scifi props? › Airsoft guns are great for
Airsoft guns are great for resembling modern day weapons, as well as some antique models, but most would probably be too realistic for your uses.
Maybe some nerf guns or other toys guns as well as your waterguns may fit the bill. Anyways, good luck!