Which weapons need foregrips, and which dont? Heres the answer.

[TORCUT]

it actually adds to the sway of your gun left and right when you shoot.

Only on weapons that have 2 different horizontal recoils. Like the M16A3. (.1 left .4 Right) But it wont on an L85A2 (.28 Left & right)
The only weapons t wont add horizontal recoil too (assault class) are
L85A2
SCAR-L
G3A3
And KH2002.
Everything else, you're right, it adds sway.