TEC-9

The TEC-9 is an infamous pistol designed by American company Intratec. Its design was supposed to be that of a open-bolt blowback semi-automatic pistol. However, due to easiness to convert to full-auto, the TEC-9 was redesigned to be closed-bolt. Apparently, the TEC-9 in this game is a fictional military variant, much like the Serbu Shotgun, as it is select-fire, closed bolt, fires a hell of a lot faster, and can accept a variety of attachments, unlike the real TEC-9, which stopped production in 2001 (apparently, the professional armies in the game were able to get a hold of the designs of the TEC-9, and converted it into a more tactical layout).

The TEC-9 is unlocked at level 50, and can be an absolute blast to use, both literally and figuratively. Put simply, it is the Hardline K10 unlocked much later, as a secondary. Its fire rate puts the PPSh-41's to shame, and the raw DPS puts the FG42 and even dual pistols' to shame, even when suppressed. With a steady supply of ammo from other dropped pistols, you will be demolishing primaries if you are accurate.

FactionGuerrilla

 * Optic: Mini Sight- It's small and accurate. What else do you want from it?
 * Barrel: Suppressor- On the TEC-9, a Suppressor doesn't really seem to hurt it so I put a Suppressor on.
 * Other: Laser- Lasers help with hipfiring and the TEC-9 is no exception.

CamaroKidBB
Running the TEC-9 vanilla is fine, but attachments can help.

Spec Ops

 * Optic: Mini/Delta/Default Sight- Any of these sights is a good choice. Delta for the slim frame higher atop the gun, and the Mini for a simple dot.  However, you can also use no sight at all to minimize zoom.
 * Barrel: Suppressor- Stealth is critical, especially if you are using a secondary. After all, you don't want 50 people on your tail after you kill one.
 * Other: Laser- There's nothing else to put on, so why not? Besides, it looks tacticool.

Offensive

 * Stick to CQC. Close quarters will let you melt your foe and be able to keep close to your foes' dropped ammo.
 * Reload whenever you can. The TEC-9's magazine gets swallowed whole extremely quickly.
 * Use any suppressor. The high rate of fire will negate any damage reduction the suppressor brings up.

Defensive

 * Fire away at range. The TEC becomes a peashooter from afar.

Effective Range
The TEC-9 is an amazing pistol for CQB, and is lowest recoil in class as well, lending to moderate recoil when full auto, and zero recoil when semi (doesn't excuse the damage though).
 * Full Auto: 85 studs
 * Semi: 150 studs

In Conclusion
In conclusion, the TEC-9 is a scary sidearm to face up against. Its high RoF and DPS makes it insanely good in CQC, and the fact that it can be used with all kits makes it that much more terrifying.

Trivia

 * The in-game model lacks a trigger.
 * It has the highest full auto fire rate in the game, and second highest total fire rate, second to the AN-94.
 * On that topic, it is also the quickest killing gun in automatic that isn't a one-hit kill.
 * It is the only secondary besides the Serbu Shotgun that has a magazine in front of the (non-existent) trigger.