The Kalashnikov is a staple AR in many shooters, including The Division 2. It has rather hefty recoil, which can be annoying at times, but the amount of damage it deals totally compensates for this little nuisance.
To get the most out of this gun, shoot the AK-M in short bursts so that it doesn't stray away from its target too much. As one of the best guns in the game, it can kill your opponent in short order.
The black market version of AK-M can be modified with a long, underbarrell rail and a 7.62 muzzle, but if you get the classic variant, it's going to do the job just as well.