Mouse Acceleration/Enhanced Pointer Precision bug in BO2
If you have issues with a weird mouse acceleration bug in BO2, it is likely because your mouse has it enabled within its drivers. Depending on what kind of mouse you have, go to its drivers and disable anything that's in relation to mouse acceleration/enhanced pointer precision. If you don't have the drivers installed, research them for the specific brand of mouse that you own and install it from there.
Or if you have mouse acceleration in general, disable enhanced pointer precision in your windows settings
I'm not sure if I've ever had this problem or not before, but I just found out I've had Enhanced Pointer Precision enabled all along.
cl_mouseaccel 0in console as well if your methods font work for people.