What's the gun in BO4 [PS4], and how do I get better with Scuff Controller?

What's the gun in BO4 [PS4], and how do I get better with Scuff Controller?

Well, I would say 'training' haha the more you play and the better you know the maps, the better you will be

Gamble, gamble, gamble! Study maps and remember routes! Then you always know which corner the opponents come next…