I'm wondering something and I saw this on the wiki what happens when you level up the guns skill?

Lets say the hunting rifle needs 6 str and 50 gun skill as the requirements in the wiki. If you meet the requirements is that only capping the gun's spread or does this match damage as well and is capped at this level.

Would like to know and likewise for other skills.

Link: http://fallout.wikia.com/wiki/Fallout:_New_Vegas_weapons

possible unique weapon spoilers.