I used to use this for Sn

STG-44 with Flash Hider
Perk 1: Bomb Squad
Perk 2: Double Tap
Perk 3: Steady Aim.
Right now I use these two in normal SnD(not a big fan of HC)
MP40 @ Silencer
Perk 1: Bomb Squad
Perk 2: Stopping Power
Perk 3: Second Chance
& I use a PTRS with pretty much almost the same setup for large maps.