The shooting skills are part of the game's Skill system.
Hitting your target will raise your skill level for each weapon.
Levels: 1 to 20
Higher shooting skills will let you
- experience less gun and bow wobble when aiming
- hold breath longer
- hold vertical bows longer in full draw 
As you reach a higher level of shooting you will receive an in-game message letting you know that your weapons skills level has been increased.
- Only hits on permitted species increase this skill.
- It is not the kills that count, but the hits. If you hit an animal multiple times, every hit will count.
- It is not possible to increase your shooting level at the shooting ranges.
- Most weapons require their own leveling. A higher level for one weapon does not have an influence on another weapon, even if it is the same type. For example, your shooting level of the Snakebite bow has no influence on your shooting behavior with the Parker bow.
- The general rule is: texture variation = same skill / new model = separate skill
There are shared skills for weapons that only vary in their texture.