Never used a shotgun class....always meant to use one....especially on hijacked (close quarters boat)
Personally, im a runner and a gunner, so for me its MSMC permanently unlocked, fitted with that is Laser sight and Adjustable Stock which lets me fire from hip sooo quick.
Perks are: Hardline, Toughness, Dexterity and a frag grenade.
I used to have reflex sight and silencer on, however since I switched I found the setup above worked ALOT better, almost as soon as I took silencer off. Hardcore player so 2-3 bullets kill a player, but seems to have saved a extra bullet.