10. Silenced Guns Make Almost No Noise Whatsoever
Watch just about any action movie these days where a character attaches a silencer or suppressor to their gun, and the resulting gunshot will sound like nothing more than a gentle whizz.
Case in point, John Wick: Chapter 2, when Wick (Keanu Reeves) and Cassian (Common) fire their silenced pistols at one another in a crowded train station while the general public remains blissfully unaware. Granted, it's played for laughs in this scenario, but still totally absurd.
In actual fact, silencers are only able to reduce a gunshot's loudness to a fairly limited degree.
Your average gunshot is somewhere in the 140-190 decibel range, and a silencer can reduce it by anywhere from 15-45 decibels, ensuring even a suppressed gunshot should be about as loud as a chainsaw or a thunder clap.
One of the few films to actually get this right is The Bourne Identity, for when Conklin (Chris Cooper) is assassinated with a silenced pistol at the end of the movie, the shots let out a distinctive and appropriately loud "thwack!" sound complete with a resonant echo.