Then you just pull the trigger, and the gun waits until it's perfectly lined up with the target to fire, taking into account stuff like distance and wind direction. Meaning that this thing actually chooses when to shoot itself to get a perfect kill.
"We're putting the same technology into our new T-800 robot butler. 'T' is for 'terrific'!"
In other words, novice shooters can make a target at 500 fucking yards on their first try. By the way, the use of the word "tag" here isn't coincidental, because ...