There’s a famous story from the set of “At Close Range,” the 1986 film starring Christopher Walken and Sean Penn as father-and-son criminals. In one scene, Mr. Penn points a gun directly at Mr. Walken’s face. According to the story, Mr. Walken was diligent about checking the pistol before every take to make sure it wasn’t loaded. Moments before the cameras rolled, Mr. Penn grew frantic.

“Give me the other gun,” he shouted at a crew member, who duly complied. At that moment, the director called “Action!” The terror on Mr. Walken’s...

Sean Penn in the 1986 movie ”At Close Range.”

Photo: Alamy Stock Photo

There’s a famous story from the set of “At Close Range,” the 1986 film starring Christopher Walken and Sean Penn as father-and-son criminals. In one scene, Mr. Penn points a gun directly at Mr. Walken’s face. According to the story, Mr. Walken was diligent about checking the pistol before every take to make sure it wasn’t loaded. Moments before the cameras rolled, Mr. Penn grew frantic.

“Give me the other gun,” he shouted at a crew member, who duly complied. At that moment, the director called “Action!” The terror on Mr. Walken’s face is real, and it’s in the movie.

A recent on-set tragedy, in which Alec Baldwin fired a live bullet and killed a cinematographer during a rehearsal, has many in the industry calling for a prohibition against working firearms on Hollywood sets. There’s one problem: Actors love real stuff.

A century’s worth of American film actors have been trained to re-create reality as faithfully as possible when they work. They’ll go to almost any length to contribute an added measure of truth to a scene. If a script says a character has been up all night, an actor will come to work without sleep. Actors will gain weight, lose weight, hang out of airplanes, learn the saxophone, eat bugs and have teeth removed if they think it will help sell the audience on the reality of what appears on screen.

Acting is a head game. You try to fool the audience, but first you need to fool yourself.

All drama is manufactured reality. An actor who plays Hamlet doesn’t know what it feels like to have an uncle murder his father and marry his mother. But he may have some real tragedy or misery in his own life to draw on. He uses his imagination to help fill in the gaps of his experience. It gets him halfway there.

Costumes and props serve the same function. When an actor puts on his character’s clothes, he is transformed. When you dress like a cowboy, you tend to walk like a cowboy. Most actors like to work with as few gaps as possible. Why? So it looks real. So they don’t feel phony. An actor wants the audience to look at the screen and see a cowboy, not an actor pretending to be a cowboy.

Actors themselves will probably resist any ban on the use of real guns on set. A rubber gun doesn’t feel like a deadly weapon when you hold it in your hand. It feels like a toy. A real gun has weight. It has heft. You can feel its power. When you pick one up, it changes how you behave. As an actor, you know what to do. You act differently when you’re holding a toy.

I’ve been out of the game a long time, but I still have actor friends. One of them recently sent me a link to a five-minute short in which he plays a guy who sleepwalks into the kitchen at night and drinks a healthy shot of Heinz Mayochup straight from the squeeze bottle.

“Did you really chug that stuff?” I asked.

“You know it!” he replied.

Everyone agrees safety must come first. But I know actors. They won’t give up their grip on reality so easily.

Mr. Hennessey is deputy features editor of the Journal’s editorial page. In the 1990s he worked as an actor in New York and Los Angeles.

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