Whether to use it or not is up to you but note that it is not the brightest weapon option out there. While the Mozambique can be deadly in the early game, even the developers of the game consider it unpowered. Its fire rate overdoes some other weapons in the group, and it has a bit longer range. This pistol can cause damage, although not too decent, but it reveals its damage potential only when you are close to the target. Otherwise, it is still quite bad in use and has weak characteristics even with attachments, so it is not the best choice of weapon for a victorious battle.
See Mozambique Shotgun in action