Ghost laggin for me please help!

When i am using a rifle and everything is fine but when i use a sniper and scope in it starts laggin abit.
My pc specs
Proccessor: intel core i7 4700HQ
Card: Nvidia GTX 780M
Ram: 32 GB
I tried from low to extra settings and dosent work at all
Now im running extra settings 70fps and up but sniper scoped in drops drastictly
My drivers are all updated

Turn off anti-aliasing?

i did tried turn off its still no use
i also tried windows no borders it reduced the lag abit when scoping in but still lags
I tried lower image quality but no use
and with my card I can supposed to run maxed out on this game
im playing bf4 all ultra and no lags at all
or is it a bug or some thing?
any fix to this?