Shotguns
Shotguns are very powerful at close range against both groups and single targets. They can quickly deliver a lot of damage but also have small magazines that take long to reload. The behavior of shotguns is heavily dependent on the type of ammo used, which will be pronounced even more in the future.
The game simulates every single shot in a shotgun shell, with different ammo types having a different amount of "subshots". With ordinary slugs, a shotgun turns into a rifle while loading buckshot greatly diminishes the damage at longer ranges, especially against armored targets. To get the most damage out of a shotgun, one should try to burst smaller groups at around 20hex distance to make sure that as many pellets as possible can hit a target.
What shotguns lack is range, especially when it comes to single target damage, as well as sustained DPS as they often have to reload after a few shots. In the future, the right choice of ammo will be an important factor as well, turning shotguns into a risky but quite rewarding weapon if used accordingly.