SMGs are pretty powerful secondary weapons. Hence their name, they have high fire rate, but they have low accuracy and, like most other secondary weapons, have inferior range.
Overview of Standard SMGs[]
Bizon[]
This submachine gun has good RoF and decent impact, but it is starter weapon. It can be replaced by more powerful weapons later on.
MTAR[]
One of my favorite SMGs, the MTAR has a 3-round burst, making it have a lot of DPS.
UMP 45[]
I don't really like this SMG because it has low RoF, which is ironic for SMGs.
Vector[]
This weapon has extremely high fire rate, but also very little ammo. Try not to use it until you get closer to the enemy.
P90[]
Much better than the Vector, because it has a lot of fire rate AND more ammo.