Sub-Machine Gun

The 9mm SMG is a Small Gun in Fallout: Brotherhood of Steel can be dual-wielded.

Characteristics
A very good weapon until the end of Chapter 2, which is also obtainable early in the game. It has a same damage of the Home-Made Machine Gun but the rate of fire of the SMG is higher.

Single

 * Carbon Town Center (Dusk) - Warehouse Main Storage - Mill Parking Lot, can be bought from Jesse.
 * Carbon Mill Generator Area, found in footlocker.
 * Los Bridge West, purchased from Hieronymous.
 * Los Docks Holding Pens, purchased from Salieri.
 * Secret Vault Ruins Level 1, purchased from Shop-Tec.

Dual

 * Los Bridge West, purchased from Hieronymous.
 * Los Docks Holding Pens, purchased from Salieri.
 * Los Docks Holding Pens, found in footlocker.
 * Vault-Tec Warehouse Basement, found in footlocker.
 * Vault-Tec Warehouse Basement, purchased from Shop-Tec.
 * Secret Vault Residence Level 1, purchased from Shop-Tec.