You may be looking for Tec-9, a weapon titled "Machine Pistol" in Grand Theft Auto V.
A machine pistol is a sub-class of pistol. Machine pistols are often not much larger than a regular handgun, and can fire pistol rounds at high rates of automatic fire.
They were first designed during World War I. Many machine pistols are simply handguns with the added option of fully-automatic fire (such as the Glock 18/C), and others are designed strictly as a separate weapon (such as the Micro Uzi). Machine pistols don't usually come with a fixed stock, though most allow the attachment of one, as it helps absorb recoil and increase accuracy. The light weight and small dimensions of machine pistols enable users to fire them one-handed with relative ease, though accuracy depends entirely on the shooter.
The machine pistols available in the Grand Theft Auto series are the following:
- Automatic 9mm
- AP Pistol
- Tec-9
- Ingram Mac 10
- Mini SMG
- Micro SMG (only the smaller Micro Uzi and Mini Uzi variants)