Yeah, its kind of annoying when you get hit markers when you're one shot away from a tactical nuke and somebody back stabs you because they see a red dot...
At least it trains us to be a better sniper by forcing us to aim for the chest
Another one of IW's "BALANCING" the game...
Oh, and I got 22-1 on my level 24 with Chopper Gunner

Most good guns are unlocked at the beginning, Tar-21, Scar-H, Barrett, Intervention.