Firstly, don't take out your frustration on the scope, as I'm doubtful its the culprit here. Having the same problem with a previous scope on said rifle is fairly damning evidence.
You didn't mention what rifle it was, but a Leupold STD base and rings are windage adjustable.
Lastly, do you know the history of said rifle?
Remember a Ruger Mini 30 that a buddy bought used years ago that exhibited the same issue, only much worse. In his case it was a bent barrel. When he pressed the seller on the issue, it came to light that the gun was involved in a quad accident, but being it was in a gun boot, it showed no visible signs of trauma.
https://youtu.be/wcRAX5OLtJE
Classic video lol
But gets the point across
The only advantage to a light rifle is it's weight, all other advantages go to the heavier rifle..
Definitely sounds like the holes aren't lined up with the bore.
OPotions would be trying the posi-align system previously mentioned or windage adjustable Leupold. A one piece mount that doesn't allow you to correct for it simply won't work.
I saw a video on YouTube that talked about this. Something about seating the prism or whatever. I tap my Trijicon whenever I make an adjustment.
"The budget should be balanced, the Treasury should be refilled, public debt should be reduced, the arrogance of officialdom should be tempered and controlled, and the assistance to foreign lands should be curtailed lest Rome become bankrupt. People must again learn to work, instead of living on public assistance." Cicero - 55 BC
..... The NDP approach: if the facts don't fit your ideology, just pretend the facts don't exist.......
The only advantage to a light rifle is it's weight, all other advantages go to the heavier rifle..
Check to make sure that your scope has been mounted with the elevation adjuster on the top and the windage on the right hand side. I saw a guy at the range who had his scope mounted 90 degrees to this with windage on top and elevation on the left side. No matter how much he dialed the windage it still shot to the right with the scope in this position.
Semper in excretum altum