I've recently been tooling around with the shotguns. I was kind of surprised to see that there are some long range scopes available. Especially for a weapon with such a limited range. Does anyone have/use these upgrades for the shotgun and are they even worth using?
Coupled with the "Slug" ammo, you can do some serious damage with a scoped shotgun. It's got both short range lethality and long range damage.
There's some NSFW language in this video, but the guy's having fun with it, so:
Shotguns do small amounts of damage at range, but if you've got one that's semi- or full- auto, you can take people down faster than you'd think. When you factor in latency, shotguns with pellet-style ammo can sometimes win simply because they fire more bullets simultaneously.
Put a scope on your shotgun and load it with slugs. At close up it's close to the same damage as regular shotgun spray, but then you can snipe with it as well. Sniping with a slug you can still perform kills quite well. Search Google for 'Battlefield 3 shotgun scope' to see videos of it in action. Some people really dig the configuration.