So hear me out. The Drilling is not included in any of this. Also note I am not a shotgun camper, I actually push.
Shotguns are a weapon class that have lengthy reloads and are only effective up to 8 meters(ish). Spread make it hard to measure. The Suomi kills with a ttk that is nearly identical, and is more forgiving. It is more effective at range as well. Medic also has infinite heals to help with cqc, support does not. Shotguns are rather underpowered as a result.
Now I want to add a nifty little feature-changing the fire mode dumps your shells out the bottom of the gun, and you load slugs. This would obviously take a few seconds. Only one specialization would need adjusting, so the slug spec would become high velocity slugs, with a 350 m/s velocity(normal is 300).
Ammo counts should remain the same, so the total ammo should be cut to 15,15(normal,slugs) from 30 shells, or 20,15 from 35 shells.
Shells are loaded one at a time. So hitting the reload button when at 5 out of 7 shells should be able to stop us from adding more shells.
Remember, shotguns are and unforgiving weapon class that is currently cqc only, and has less range than a suomi wich is more forgiving, just as effective, has unlimited heals, and has longer range.