SG or Ak?

Well, it depends on how you play the game, if you are an entry fragger or you like to challenge, ak is the best weapon for you. Now, if you a guy for mid/long distance shots and like to hold angles, SG is better.
AK has better rate of fire, its a 1 headshot kill no matter if you have helmet or not
SG has better precision but rate of fire and spray control is worst, its a tap/burst gun.
I would say with their pros and cons, adapted to each style, they are equal.
I prefer the AK tho