It isn't the armor piercing rounds necessarily. It's that combined with the final round perk which is a one shot kill anywhere on the body. If your argument is to compare to other games with snipers in it that have one shot kills, the closest main stream game I've played like that is COD. While this is similar in some regards, it is very distinct in others. COD also has it's one shot kill snipers when you hit torso and up. This gun can one shot you in the foot. Not necessarily saying it needs to get nerfed, but there is a clear and obvious advantage this gun has over all other guns in the entire game. Fittingly it's only sold thru iron banner and takes a while to roll properly.