Aim

One of the most important rules they teach you in gun safety is that you never aim a gun at something you don't plan to kill. So you aim for the torso. The largest part of the body. The smaller parts of the body are harder to hit. There's a much higher chance that the bullet misses and hits something else. Hits someone else. So, even though Stiles didn't need to consciously aim, his reflexes, reflexes perfected from years of going to the gun range with his dad on weekends as a kid, hours spent at the range on his own, perfecting a skill he knew he would need now in this insane world he'd somehow stumbled into one night in the middle of the woods as a stupid teenager with more curiosity than fucking brains...those reflexes did it for him.===Stiles kills a hunter.