I have worked on stage and screen as a theatrical armourer, and good quality airsoft replicas were a god send, as they tend to be lighter than real steel or blank firing replicas, so the actors can have a airsoft pistol in a holster for long periods of time without it being uncomfortable for them and looking uncomfortable (remember most actors don't walk around in their real lives carrying a heavy pistol on their hip or under their arm.), and speaking from an armourers point of view, if an airsoft gun goes missing its nowhere near as big a problem as a real steel gun going missing.
On the ot