For safety reasons, no real weapons are used on film sets, but - in simple productions - dummies or, if it is to look realistic and sophisticated, special prop weapons. They work with blanks, but still have similar loading and recoil behavior as real weapons. A recent tragic accident in the USA shows just how dangerous such weapons can be.
During the shooting of the western "Rust" the camerawoman 
Halyna Hutchins was fatally injured and also the director Joel Souza was hurt (but he is now released from hospital) when leading actor Alec Baldwin fired a shot from a prop gun -- exactly how the accident happened is not yet known, but the phrase "Baldwin shoots camerawoman on set" (as used by the Tagesschau, for example) might be misleading, since presumably no live weapon was involved.
As an interesting Twitter thread by firearms expert Lars Winkelsdorf explains, guns are specially modified or prepared for movies, for example, to artificially create the missing recoil, even though no real bullet is fired at high pressure. This is done by equipping the weapon with a gas nozzle - but if it malfunctions or is not installed correctly, it can become a projectile itself, with a completely unpredictable trajectory, and thus hit people on the set, even if - following safety rules - they should never be aimed at it.
When working with such film weapons, special safety precautions should always be taken, such as wearing protective equipment - even though there are "only" blanks in the magazine. The exact cause of the accident and whether regulations were disregarded on the film set are still being investigated.
Originally from Ukraine, Halyna Hutchins gained her first experience shooting British documentary productions in Europe. In 2015, she graduated from the American Film Institute and worked on several short films before shooting 2020's "Archenemy," a superhero action film starring Joe Manganiello. She was named one of the "Rising Stars of Cinematography" by American Cinematographer in 2019.
Halyna Hutchins
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