Why do people shoot their 銃 sideways?

That's a good question, why don't あなた go ask a person with a gun that. XD kidding. Idk tbh.

Kill shot! It's a kill shot!

Refraised from a gang-banger"To look gansta"

It's just for appearances in order to look menacing to victims. It makes the gun less accurate, but it doesn't actually matter at close range.

Has it's roots on automatic weapons. When they shoot no doubt there's recoil and によって flipping the gun sideways the recoil allows the weapon to spray the shots effectively covering a greater radius, although it's not accurate so this tactic can be a hit または miss.

It makes them look cooler.