Barrett with
FLG's and Thermal Scope (thanks to the Bling perk) and I regualrly cycle through the various Machine Pistols and Shotguns dependent on game mode and challenges ^^ I also have the Pro version of steady aim (so I get elongated hold breath as well) and the extra bullet penetration (overkill with the
FLG I know, but I like to put my opponent down and leave him there)
I also have Painkiller, cause I also die quite alot