The Vector .45 ACP is described in the game as:
A high-tech, low recoile SMG
You can find the Vector in north-east Media Luna province, inside Unidad F.O.B. Buitre, at the eastern edge of the base in an armoury by the main entrance.
If you want to sneak into the base, start with taking out the snipers in the towers. There’s an outer fence around the base, and I initially snuck through a hole in the northern perimeter, but later discovered there’s an easier way in, using the southern main entrance to the base. Just one entrance guard and you can sneak in and around the eastern edge of the base to the armoury.
You can’t use your drone as there’s a jammer, and Unidad never sleep – day or night, so there will be guards to take out, but be patient.
A high rate of fire and good handling make this a formidable short range weapon. It also has select fire options for full auto, three round burst and semi auto.
The Vector accepts all SMG accessories, but will look best – in my opinion – with a small scope, vertical foregrip, extended buttstock, a suppressor and extended mags.
The Vector’s weakness is it tiny 15 round standard magazine, but a 25 round extended mag is available, also in Media Luna.