They do. It depends on the production. Studios are more than capable of cgi'ing the flash of a gun firing a bullet. That probably costs more money than firing blanks and is probably harder to act to since they would then need to "imagine" the gun shot.
How does Hollywood still not have a prop gun that cannot hold or fire actual projectiles?
They do. It depends on the production. Studios are more than capable of cgi'ing the flash of a gun firing a bullet. That probably costs more money than firing blanks and is probably harder to act to since they would then need to "imagine" the gun shot.