Foregrip
Vertical foregrip that reduces recoil.
The Foregrip attachment helps reduce the spread of your weapon very slightly. In general, you should take this attachment only on weapons you plan to use at medium range or longer, particularly weapons with unruly kick.
At shorter distances, minor bullet deviation is rarely an issue, and as you need to be ADS to get full benefit from the Foregrip’s visible recoil reduction, you won’t always be using it when hipfiring at close range.
Quickdraw
Custom grip for fast Aiming Down Sights.
Quickdraw is a powerful attachment for any CQC build. If you expect to engage enemies at close to close-medium range regularly, you want to take Quickdraw.
While the advantage amounts to fractions of a second, any edge you can get in close-range firefights that are lethal almost instantly is a benefit.
Quickdraw also makes weapons feel slightly nicer to use, although this usually won’t actually help you in most medium- to longer-range engagements.
Stock
Increases maneuverability while aiming down sights.
A powerful attachment, the effect seems simple, but the impact on your opponent’s ability to track you while you are ADS is significant.
For this reason, Stock is recommended on any build where you plan to engage in close-medium to medium-long-range firefights regularly.
At very short distances, the movement increase is rarely relevant when hipfired shotguns and SMGs are a threat. At very long ranges, your relative movement is still fairly easy to track for someone with a sniper or LMG.
Laser Sight
Reduces bullet spread when firing from the hip.
A useful attachment for CQC, and can be useful on some weapons even out to close-medium range.
The Laser Sight is also useful if you are a very jump-happy player. If you make heavy use of your Rig’s thrusters to jump over your enemies’ heads constantly, the Laser Sight can help keep your hipfired shots on target while you’re rocketing around the map.
This seems like an obvious attachment for shotguns, but because it tightens the spread, this can actually make you miss a shot you might have otherwise hit if you were slightly off target. And because most shotguns take more than one shot to kill anyway, you often care more about getting any pellets on target more than hoping for a guaranteed one-shot kill. (At truly close ranges, you’re going to score lethal shots with the pump shotguns almost regardless of where you aim).