Shotguns in this game have gotten a rather bad rap and it's a real shame. They are wonderful weapons and work quite effectively if you can force shorter range engagements. The shotguns in Ghost are a little stronger in general than they were in black ops 2 with the exception of the KSG from the previous game. Even with slug rounds none of them seem to match the range of that weapon. However, a few of them come close. The shotguns are a little different than in previous COD games, however the same strategies still work well.
Each of the shotguns fires an 8 pellet spread where each pellet does a set amount of damage based on the range you are from the target. Normally a one hit kill requires multiple pellets to hit the target. The FP6 can kill with a single pellet hitting at barrel stuffing range, but almost all the time you need to his with about half the pellets from a single shot at close range to ensure a one hit kill. ADS with a shotgun will tighten your shot spread some, however, with the exception of the tac 12 it's less than in the previous Black Ops 2. The shotguns also handle slightly different in this game than in the previous one as well.
First of all, the shotguns have higher pellet damage than in black ops 2. This means it requires less pellets to kill in a single blast than the previous game. However, without the tighter ADS spread this leaves you with a lower probability of hitting with multiple pellets in a single shot. When running and hip firing the Shotguns still move at full speed and have a reasonably tight hip fire spread. They also ADS at the same speed as an SMG .2 seconds. However, once you ADS your movement is slowed down to about the same as an assault rifle which, I believe is around 40%. This leads to two workable strategies while using a shotgun as a primary weapon.
Which build you choose depends on your preference in ammunition. The slug rounds extend the reach of the shotgun by about 60%, however, you don't get the buckshot spread and it's an all or nothing shot. The Slugs have a one hit kill range on most of the shotguns out to about 8 meters to any point on the body. After that a hit to the upper torso or head will generally be the only way of killing in a single shot. That means using slug rounds basically turns the shotgun into a very short range sniper rifle with considerably better handling. Which, option you choose is up to your preference and play style.
If you are using buckshot and any shotgun but the tac 12 your build is pretty simple. You want the muzzle break on the weapon and extended clips if they are available for that weapon. You need a fast class using speed perks such as agility, marathon, ready up and dead silence to allow you to rush and flank the enemy for a close range hip fire hosing. If you are running slugs, you need to treat the weapon more like the other guns in Ghost, you have two good options. One is to run quickdraw with the above listed speed perk. Instead of hip firing you want to get close than quickly ADS an opponent and fire at them. The other option is to run stalker and fire while keeping your sights up. Both work well and can turn the weapons into very competitive tools in the correct situations.
The key to competing in this game with the shotguns is speed and positional range advantage. When running a shotgun, you want to keep to the areas of the map where your weapon can compete well. You want interior location or areas where you are between two walls or objects no further than 20 meters apart. If you head out into the open and somebody sees you, you are a sitting duck. However, if you can get close enough nothing else in this game stands a chance. Last night, I was playing cranked on octane. I ran up against 3 other players with the fp6. Luckily then had 2 assault rifles and a sniper. I got a triple kill and kept moving. Most players don't know how to fight against shotguns in this game, and having one in your hands usually wins you gun fights. However, you have to build your class correctly and choose your path very carefully.
There are 5 shotguns. The bull dog shoots the fastest and has the biggest mag. However, it has the lowest damage and the shortest range, it's good on small maps like strike zone and free fall. The MTS is the other semi-auto shogun. It has a 5 round clip and fires a little slower than the bulldog, but it also has a slightly longer range and a little higher damage. The FP6 is the highest damage shotgun and offers a more consistent kill at close range. However, it has a limited magazine and less range than the Tac-12. The Tac-12 offers less damage than the FP6 but it's spread tightens better with ADS than any of its peer and it has a very generous magazine. It has the furthest reach of the shotguns but lacks the semi auto fire of the first 2 and the raw damage of the FP6. They all work well, but you have to choose the one that fits you best and play them in the areas of the map where you have the close