First off, the magnum in Halo 5 has two circles, one where the bullets go, and another larger circle that, from what I can tell, initiates stickiness to your reticule, whether this is aim assist or auto aim I do not know, but it doesn’t matter. The facts are that your reticule with the magnum gets sticky when in all actuality the bigger circle can be on someone whilst the smaller is not, therefore initiating stickiness when you will not hit your target.
In my opinion, this is why when combating someone who crouches over and over, it is too difficult to kill them simply because moving your reticule takes longer because the game says so. Just think about it for a minute, if you have your reticule on an enemy’s head, and he crouches, your reticule is still sticky even though you can’t hit him.
If what I said is true, which I am positive a t certain ranges that it is, then this is a very poorly inserted mechanic in Halo 5, and also doesn’t just effect players when their combatant is crouching, but also when jumping, strafing, and even clambering.
I would lastly also say that this mechanic was built in to the game to secretly help noobs, by making the “sticky” bubble larger than it ever has been in any other Halo game, so that it slows down noob’s reticules when they are jerking from left to right, or up and down, and in turn, screws up your average Halo player because they are used to snapping to enemies, where-as in Halo 5 the game’s immense stickiness screws you up.