In a studio near Los Angeles, a group of filmmakers practice framing a close-up of a rubber gun held by an actor when they are suddenly interrupted.

"He's pointing the gun directly at the crew – it's exactly what happened on 'Rust,'" said Dutch Merrick, a veteran armorer who offers training on gun safety in movies.

"Who's going to raise that and speak up if they see this situation?" he demands.

Merrick refers to the infamous tragedy in October 2021 on the New Mexico set of Alec Baldwin's low-budget Western "Rust."

That day, Baldwin pointed a prop gun toward cinematographer Halyna Hutchins. He believed the revolver contained only blank bullets, but a live round struck Hutchins.

Baldwin goes on trial for involuntary manslaughter this Tuesday.

"It was a wake-up call to me," said Virginia Brazier, one of the group members attending Merrick's training course.

She works as a production manager, responsible for hiring film crews, including armorers and prop masters.

"I want to know what questions to ask people to make sure that I'm vetting and doing proper recruiting to ensure that we're safe on set," she told Agence France-Presse (AFP).

Golden rules

During the course, Merrick underlines that Rust was "underbudgeted." He believes that led to a series of failures, culminating in an "industrial accident."

He teaches students simple ways to help identify blank bullets, such as their characteristic ridged tips.

And he makes attendees learn and repeat aloud the three "golden rules" of gun safety.

Always point the gun in a safe direction. Always keep your finger off the trigger until ready to fire. And always treat a firearm as if it were loaded.

These are valuable basics for an industry set on edge by the "Rust" tragedy, said Ryan Taylor, an assistant director.

"A lot of the crew members, in general, are just a bit more nervous," he said at the workshop.

Crew members often now want to inspect props themselves, and want any rounds contained within prop guns to have been "fully shown" before use, said Taylor.

While the "Rust" tragedy prompted some calls for banning firearms from sets altogether, Hollywood has generally preferred less radical measures.

Industry guidelines on firearm use were revised for the first time in 20 years last winter. Among other changes, they now specify that only an armorer can hand a weapon to an actor.

On "Rust," prosecutors said Baldwin was handed the gun by the film's first assistant director, who later pled guilty to negligent use of a deadly weapon.

California will also require productions seeking state tax credits to hire a security advisor. The trial measure will be applied from next year through 2030.

Overcorrection

Nonetheless, some productions have decided to give up on real firearms altogether.

"Walker," a recent reboot of the popular 1990s TV series "Walker, Texas Ranger," and the cop show "The Rookie," both used only "compressed air" guns or rubber weapons.

Action superstar Dwayne "The Rock" Johnson announced that his production company would no longer use real guns.

Instead of shooting blank bullets on set, the flash and bang of gunshots would be added later using computer effects.

The extent of these changes felt across the industry is difficult to quantify.

AFP asked a major Hollywood prop maker to confirm reports of a significant drop in gun rentals, but the company declined to comment.

"There was a severe overcorrection that didn't need to be made in the way that it was," said Merrick.

As an armorer with three decades of experience, Merrick believes that real guns – when used safely – give both actors and audiences an unrivaled sense of "authentic action."

For example, he said it is impossible for performers using rubber guns to accurately emulate the recoil of a gunshot.

Compressed air guns – or "airsoft guns," which do not fire metal bullets – create a "false sense of security" but could theoretically be lethal if used incorrectly, he added.

Yet, with Baldwin's trial about to begin, Merrick fears the mistrust of firearms on movie sets could grow further.

"It's going to have an odd effect on performers if he's convicted," said Leilani Barrett, an actor attending the course.

"As an actor, I'm thinking about hitting my mark, memorizing my lines, doing my character, following directions.

"The last thing I want to really worry about is the prop that I'm using."