According to some "sources" there's a lot of support for quickscoping and while I don't agree in the least I think that there is in fact a group that enjoys quickscoping and that they too should have a least some voice.
I propose a radical system for quickscoping that will hopefully make this insanely stupid (personal opinion) style of play less frustrating and take a least some skill to use. It's an all or nothing quickscoping class loadout.
Using a single perk that takes up all class slots a player can use a specific sniper in conjunction with said perk to be able to quickscope. The catch is this player cannot take advantage of any other perk or equipment options. The player has to use one specific rifle that's specs are tailored to the all-ranges OHK potential weapon. This weapon has slower mobility, harsh accuracy, trigger delay, and OHK only to the head, neck, and upper chest.
The trade off is a fast ADSing sniper rifle.
The reason for the lack of CaC choices is simple. This tactic should not be made even easier by combining an already easy tactic with perks that give a QSer even more ridiculous abilities. The lack of options for the sniper rifle ensure that the ADS time isn't further reduced because of equipping an ACOG scope which also allows for quick adjustments due to the shallow magnification of the sight.
The lack of equipment and secondary prevents spamming and taking the easy way out when you know you can't win by QSing. If you're going to go spamming a sniper then you shouldn't be allowed to spam explosives too. The trigger delay means a QSer has to make each shot count. No more panic scoping. You cannot fire the gun from the hip, while ADSing, only when the scope is fully 100% scoped.