You won't find many people brave (or stupid) enough to be shot at in the name of science but that's exactly what one physicist did in an experiment to see what happens when you shoot a gun underwater.
Physicist Andreas Wahl posted a video on YouTube showing him standing in the middle of a swimming pool with an assault rifle aimed at him from 1.5m away with the intention to discover what happens to a fired bullet under the effect of water.
When Wahl pulls the trigger on himself using a specially rigged piece of rope the bullet bursts out of the gun with as much power as it would above the surface but it almost immediately is slowed to a halt after a few centimetres and sinks to the bottom.
The impressive experiment shows how the velocity of a speeding bullet is dramatically slowed as a result of the water molecules being closer together than in air and thus creating far more resistance against movement. We all know it's harder to move in water than out of it but the extent to which it slows something as streamlined as a bullet is far more impressive than we imagined. Why he has to stand in front of the gun we don't know but it adds to the effect and it's a good watch.
This bout of brave ballistic mythbusting now gives us the ammo to call out all those Hollywood movies where gunfights take place underwater. We're looking at you, James Bond.