Tommy gun (Fallout 2)

This Thompson M1928 submachine gun is a sinister looking weapon; every time you hold it, you have an urge to put on a fedora hat and crack your knuckles. The Thompson is well-fed by a large 50 round drum magazine.

Both Shark Club and Desperado bouncers in New Reno have this gun, though you need to kill them for it. It can also be found in various random encounters in the area around New Reno. Eldridge also stocks the gun.

Like the M3A1 "Grease Gun" SMG, the usage of this gun is limited by its rather heavy ammunition. Furthermore, the Grease Gun has better damage, longer range, and requires 1 less AP to fire. The only real advantage the Tommy Gun has over the Grease Gun is that it carries a larger magazine. '

Fallout Tactics
In Fallout Tactics, this weapon is notable in that it takes fewer AP to fire in burst mode than in single shot mode.

Thompson M1928