The pistol is mainly used at the start of the game, or later when the player has run out of ammunition for better firearms. In its original form in GTA 1 and GTA 2, the pistol is one of the least effective firearms of them all, firing only one bullet every second or so, at a rate slower than a machine gun. From Grand Theft Auto III onwards, the pistol is given generally poor stopping power, average accuracy, and a fairly short range. In Grand Theft Auto: San Andreas, Grand Theft Auto IV, Episodes From Liberty City, and Grand Theft Auto V, the weapon is significantly more effective, partly because it's possible to kill a target in one shot to the head; also, in GTA IV, EFLC, and GTA V, the pistol can be used as a drive-by weapon. In every game since GTA III, this weapon is the standard armament of many gang members and all police officers on patrol.
In GTA 1 the pistol's HUD image appears to be a Soviet Tokarev TT-33.
In GTA London 1969, the pistol's HUD image resembles a nickel-plated Browning Hi-Power. At the time of GTA London (1969), the Hi-Power would've been one of the main service pistols of the British Army. As such, this makes the availability of the pistol in the game chronologically accurate.
In GTA III, GTA Vice City and GTA San Andreas, the pistol resembles a Colt M1911 in shape, and its magazine capacity ranges from 12 rounds (in GTA III) to 17 rounds (GTA Vice City onwards). All of this is despite the fact that the Colt M1911 isn't commonly chambered in 9mm and, even if it was, it still possesses a single-stack magazine design, therefore making it impossible to fit 17 rounds into the magazine without completely redesigning the weapon. It is seen carried by Ray Machowski in the mission "Crazy 69" of GTA Liberty City Stories, but is not available to use in-game.
In the introduction cutscene of GTA San Andreas, where all three members of C.R.A.S.H. arrest Carl Johnson; Jimmy Hernandez and Eddie Pulaski are holding Glock 17s, instead of Colt M1911s like the ones in gameplay. Given the fact that the in-game pistol's magazine capacity (17 rounds) is incorrect for a Colt M1911 but correct for a Glock 17, and the fact that the Glock really is a 9mm pistol, it may be that the developers originally intended the player to use the model seen in the cutscenes, but this feature was left out for some reason. The Glock 17 can be used in-game by switching and swapping the pistol's model/texture with the Glock's one.
In GTA Liberty City Stories, the pistol resembles the Glock 17, while in GTA Vice City Stories, the pistol resembles a Beretta 92.
In GTA IV and EFLC, the pistol resembles a Glock 22, which is the full-size .40 S&W model commonly used by law enforcement. While the real-life Glock 22 has a standard 15-round magazine capacity, the in-game model incorrectly has the 17-round magazine capacity of the 9mm Glock 17. The sights on the model are incorrect; the gun's front sight is a duplicate of the twin-post rear sight.
In GTA Chinatown Wars, the pistol's HUD icon suggests it's a Glock 17 with wooden grips.
In GTA V, the pistol resembles a Taurus PT92, distinguishable from the similar Beretta 92FS by its frame-mounted safety (the safety on the Beretta is on the slide). The real-life PT92 uses a 17-round magazine, yet the in-game version is limited to 12 rounds for the standard magazine or 16 rounds with the extended magazine. Also, the in-game description incorrectly describes the Pistol as a .45 caliber handgun whereas the PT92 is chambered in 9mm.
In many of the games in the series, variants of the entry-level pistol exist. In GTA San Andreas, for instance, the player can acquire the ability to wield two pistols at once, and there is a modified pistol with a sound suppressor. In addition, most of the games in the series have at least one more powerful, larger-caliber equivalent of the pistol, such as the Python or the Desert Eagle.
If in the hands of a skilled shooter, the pistol can be very effective given its weak power, decent accuracy, & mid range distance.
Downtown - Next to a statue south of the dirt track.
The Glock (referenced as Pistol in-game) can be purchased from the back-alley gun shops for $600, and each additional magazine is $35. The Glock can be purchased from Little Jacob for $420, and each additional magazine costs $25.
East Hook - Can be found on the first-floor ledge of a cylindrical silo-type structure off Mohanet Ave. The player can easily reach it with an SUV/MPV or other tall vehicle like a Cavalcade or Ambulance.
Willis - Can be found behind and to the left of the parking lot off Freetown Ave. This parking lot is also located to the left of the small parking space where you obtain Stevie's Comet during the mission No. 1.
Northern Gardens - Can be found in the ladies' powder room of the Triangle Club. Please note: this pistol should be obtained only as a last resort, because otherwise the player shall receive a one star wanted level and the patrons and guards will begin shooting.