You're welcome.
In a similar fashion, you'll often see someone in a movie rack the slide of a mag fed gun.
Semi-automatic weapons do require you to rack the slide to chamber the first round after you swap magazines. When you fire, the recoil will automatically eject the casing and chamber the next round.
Bolt-action weapons, like sniper rifles, require you to manually eject a round and chamber a new round after each and every shot. You see a lot of movies violate that.
The biggest movie violation is the silencer. Silencers don't work on sniper rifles... the bullet is supersonic, it's going to produce a sonic boom. Silencers are literally destroyed after just a half a dozen shots, and they aren't nearly as effective as portrayed.
Finally, the sound of the action cycle is pretty loud in itself. Think about how loud it is when they rack the slide. That happens every time you fire.
A guy hammering a nail is still quieter than a "silenced" handgun.