Pistol
From WikiGTA - The Complete Grand Theft Auto Walkthrough
The pistol, sometimes refered to as the Colt 45, 9mm or nine is the most basic fire weapon in GTA and is available in every GTA. The pistol is not as powerful as other guns, but it is cheap, easy to get and you can shoot it while walking. You can buy a pistol in most Ammu-Nations and changes are you'll acquire it during one of the earlier missions of the storyline.
In GTA San Andreas, you'll reach 'gangster level' at 10% weapon skill, and 'hitman level' at 100%.
