I've had this issue too, the (albeit not effective) way I fixed it is by changing my dpi dynamically when I scope into the sniper, judging by the amount of views on this post I see some other people have had this issue and I am yet to find a permanent solution. I would love to know if there is one as I also experience this issue.
(Sorry for the relatively late reply, forum posts with no replies like this tend to be hard to find)