I'm not an armourer but I am around guns on film sets regularly and I've been instructed by a film armourer as to safety procedures.
There are times when I hold some responsibility for units taking shots that feature firearms ( an actor firing a gun in close proximity to another actor or shooting themselves in the head etc).
These are inevitably done without any ammunition in the guns with the actors miming the shooting and recoil ( very slightly so as not to overplay it) . The flash and slide reciprocating and cartridge ejections then go in as VFX later ( easy peasy its a junior artists job).

However if I'm on set as the vfx supervisor I'm usually shown the gun by the armourer to verify that its unloaded.

The procedure to follow is ; armourer announces "firearm on set" usually followed by "no rounds" . The phrase "cold gun" is not one I have ever heard on a film set as all guns are considered and handled as if loaded at all times as a safety protocol even if they are known to be unloaded. Before passing anyone a firearm the armourer will present the weapon and demonstrate its unloaded or unload it before handing it over ( the only person on set who will load the gun before passing it to an actor will be the armourer).

The armourer will unload the magazine and show it to the relevant person and confirm its status for example "three rounds" before reloading it and passing it to the actor or whomever . If the gun is supposed to be unloaded the armourer will do the exact same thing regardless of knowing that its unloaded . Mag out , present the empty mag , slide back , present the breach as being empty and also insert a finger to doubly confirm no cartridge is in there.

If it's then passed to anyone ( and it only gets passed to people the armourer has checked out) then they are expected to repeat the same procedure ; mag out and verify its state , slide back and verify the breach is unloaded.
If that person puts it down the next time they pick it back up even though its not been touched by anyone else and is in plain view they repeat the status check on the gun ; mag out , slide back , verify its empty.
If they then pass it back to the armourer same procedure check the status and show it to the armourer , the armourer will repeat the procedure before securing the gun off set.

For a revolver similar procedure , cylinder out verify its empty , visually confirm nothing is in the barrel before closing the cylinder.

This is one reason that firearms on film sets do not normally have plugs or grills in the barrel as the plugs themselves have the possibility to become bullets if they malfunction. Real guns are generally used on set as they are actually cheap , robust and because the manufacturing tolerance are safer than using a replica. If an actor needs to be active with a gun that is not required. Its usually a rubber gun cast from a real one , airsoft guns and replicas are generally not used as they can be a safety risk if they break and splinter and also are comparatively expensive compared with even the real gun.

Basically every time the weapon is picked up or put down its state is checked by all parties involved.


"firearm on set" is usually then announced
"there will be gun fire on this take" is usually announced by the 1st prior to the cameras rolling.
Earplugs are handed out to the cast and crew (usually macho numpties who don't spend time on action films will refuse them and enjoy tinnitus later.)

The guns are never discharged directly at anyone always off to the side ( ideally) and if its within about 15 ft then usually no rounds are used and the actors mime it and the flash and cycling goes in as vfx later .

The armourer will collect the guns after the take , check them , including running a brush through the barrel if they are not happy with the visual confirmation and reload them if required . Actors who need to be depicted firing a gun to empty and then reloading it are given tuition and rehearsal beforehand and the armourer is always close by monitoring.

There are also low powered utm rounds which can cycle the slide and which are becoming more common that stage blanks , the difference being that you won't get a flash but the actor gets some recoil to work with and the guns will cycle . However these are still treated the same as live stage blanks from a safety perspective
https://www.youtube.com/watch?v=-OmbW8dauAA
https://www.police1.com/police-produ...NixOWqdXp8g5T/

On two occasions on non UK film sets I have checked guns that were to be used when actors were shooting themselves or someone else at close range and found a live blank loaded in the breach . These guns were mag out and even had tape over the slot ( which I felt was a bit unnecessary compared with just using an empty mag) ironic they went to that trouble and then left a round up the spout. Thats also why if I'm required to put the gun activity in on a shot with an actor with a firearm up at their face I always insist on checking the gun and the armourer always knows why and won't question it.

I've seen one director who was messing around with a blank loaded firearm to the extent that I finally took it away from him unloaded it and handed it back to the armourer who was to meek to do it himself ( this was also an Indian film)

Generally speaking the gun safety on a UK film shoot is taken extremely seriously . I can only assume that this production Rust was rather low end . Whoever handed over the gun to Baldwin is ultimately the person in the wrong; but the armourer should also not have had guns lying around and an AD thinking it was okay to grab them.