I reported the issue with the Scorpio Scout about a year ago, and now I'm getting the same issue with the MSR. I was also able to confirm it on the standard Scorpio after using it for a while.
Occasionally, bullets will fly wide off the mark on these rifles until you switch away to another weapon (such as your pistol), fire a round, and then switch back.
Here's the video I sent in previously of the Scorpio Scout: https://www.youtube.com/watch?v=WeKXT0B_foE
And, here it is with the MSR: https://www.youtube.com/watch?v=LGnog_6aObg (you'll see it at about 10 seconds).
I've yet to see this in the issue tracker, but it makes these rifles nearly useless, because you can't rely on them at all. I'd hardly consider this a feature, given that Breakpoint is far from a hardcore milsim game with accurate mechanics. Support had confirmed the original Scorpio Scout issue when I sent it in, but I haven't seen a single inch of movement on it, so I'm making a public post about it to get more people to confirm.
It can take a lot of rounds to reproduce; I've put through hundreds of rounds in the MSR, and only saw it one other time, but when it happens, it continues to happen until you switch weapons as I noted before.