A good post explaining further
Halo 5’s aiming system uses a two-turn aiming mechanic where it differentiates between you actually aiming on a target and turning speed to look around. This has been proven inconsistent and it is the only FPS shooter that I know of that uses this type of aiming system. They claimed they changed it because in previous Halos it was a little hard to aim long distance and wanted something a bit more competitive based. I honestly have not had any problems in previous Halos aiming long distance and the whole thing about it being more competitive is kind of silly.
Halo 2 and 3 and every other game did just fine being competitive and no one really had a problem with it. Why try and fix something that wasn’t broken? Please 343 if you see this, please consider going back to how the aiming mechanics were in previous Halos because this one feels way too sluggish and unreliable.