Yup, I've reported this issue multiple times and haven't seen it added to the issue tracker myself; no idea if it's a bug that'll actually get resolved or not, despite numerous people having the issue.
https://forums.ubisoft.com/showthrea...R-accuracy-bug
What I find interesting is that different people experience it with different rifles. I myself have only experienced it with the Scorpios (all of them) and the MSR; I've never seen it with any other rifle. Once you experience it on a specific rifle, though, you'll always have the issue with that specific rifle, seemingly at random (although some people have been able to demonstrate specific causes).
I'm actually about to do a rebuild of the install just to see if maybe that will resolve it this time (didn't the last few times, but I'm actually in the mood to play BP again and figured I'd try).
I've had this similar thing happen many, many times with frustration. I thought it had more to do with the game not translating from hip-fire(since the spread seems similar to a hip-fire spread with a high ROF gun) to ADS accuracy properly when moving quickly. Honestly it happens so often I thought it was somewhat intended as a reflex mechanic and I'd been trying to give myself a moment between running or switching weapons to ADS. Though, it would only fix itself when I stop aiming, and then aim again. Hope this one gets fixed thanks for showing the team Orion!