Im not gonna lie, the way to become better at guns in r6 is practice, if you don't actually practice then you will never be good. For example, if you wana get good with the SMG 12, you need to learn the recoil and only use the smg 12 for at least a week. I recommend practicing in ffa arcades or standards as a warm up and eventually start using it normally and not have to even think about how hard the recoil is because you will get so good that it just becomes easy...