Since there is not a single one place where you can look this up here they all are, the format is "Weapon name (where to find them) = what they are with the perk (from what game: Doom or Wolfenstein)"

Pistol:
-Walther P38 (World at War) = Pistol (Wolfenstein)
SMGs:
-MP40 (World at War) = Machine Gun (Wolfenstein)
-StG 44 (World at War) = Machine Gun (Wolfenstein)
Shotguns:
-Double-Barrel Shotgun (World at War) = Super Shotgun (Doom)
-KS-23 (Black Ops) = Combat Shotgun (Doom)
Heavy Weapons:
-Death Machine (Black Ops) = Chaingun (Doom/Wolfenstein)
-Death Machine II (Black Ops 2) = Chaingun (Doom/Wolfenstein)
-RPG-7 (Black Ops) = Rocket Launcher (Doom)