Daewoo USAS-12 – ★★★★ Shotgun
Unlike the other shotguns, she's focused on firepower instead, with her skill basically making her go DAKKADAKKADAKKA. You would want an Acc scope on her so she can actually hit anything. Sometimes used in 1SG/1HG/3MG formations to provide MAXIMUM FIREPOWER. Tiles are a little eh for that though. Armour is average.
60 max ROF does limit her memeability somewhat. Often one of the better SGs for general use MGSG, if you don't plan on getting into 2nd salvo. If you do end up in the 2nd MG salvo, most other SG skills do come online, and some of them have better abilities. Make sure to use ACC scope so that she actually hits enemies for the knockback.
Has terrible tiles, which can be one reason why you don't want her over some other SG, although tile buffs are diminishing, so it might matter less than you think (10% FP on an MG affected by Mk23 only gives 7.3% FP, for example).