I was playing GTA-SA, and I didn't like how unrealistic the guns were. The Micro-SMGs have the same caliber as the pistol but do less damage, the sniper rifle has crappy range...
I went by a unit=a meter and 9mm=25 damage and totally redid the weapon stats.
Install by replacing the original weapon.dat with the one made by me.
PS- NPCs (cops, criminals, gangsters, soldiers, etc.) also get improved stats, so watch out: the stats will make a lot of missions a lot harder.
Mod on my site I submitted this mod 2 days ago. The moderators take forever in reviewing (there was a Steyr Scout I wanted a few weeks ago that still isn't available) so I won't make you wait. mrjjfeu.webs.com : the mod is right on my homepage.