If you're aiming your paintball gun correctly, out to about 60 feet, you should hit your target.  After that, the farther away the target, the tougher it is to hit what you aim at. Paintballs just don't fly straight all that far when there's the wind, and other reasons to make the balls curve in flight.

Benefits of a Tactical Vest
There are many benefits of wearing a tactical vest during paintball.  First of all, it is a great way of carrying a large amount of ammo.  This is important when playing in a large scenario game; in most of the ones I've played in, I had to carry most of my paintballs with me when I went out on a mission.