I noticed when I ADS my gun none of my bullet's hit the enemy and I prolly get like 2 or 3 hit marks but the rarely go down why do my bullet's never hit the enemy even do i see either my cross hair on them or my Iron sight any help or tips on why this is happpening

Yes indeed: When you're aiming at someone, it is best to shoot a few controlled bursts, as well as rest for a half second before taking the shot- This allows your crosshairs to settle and improves your accuracy.

The main thing to keep in mind is that: spraying your gun is going to make it very inaccurate, you have to fire single shots. Often times hip-firing will be more appropriate, aim-down-sight should be used only in a few scenarios (I believe the difference is marginal)

Staff Officer S_h_a_r_k_93