I have stated several times I would not buy a new Ruger, Marlin, Remington or S&W due to QC issues.
Yes ,you may get a good example that works or not.
There has been speculation if Ruger was going to bring back the marlin 39. Well , I am here to tell you that the production gunsmiths that assembled those guns are gone forever, from Ruger ,anyway.
As blackheart says, Ruger QC has been hit or miss for 40 years.
I have some older Ruger pistols the newest would be manufactured in '69.
I wanted a rifle for .17WSM......I ended up with a Ruger 77. Still trying to get it to shoot.
Of course, I have a good amount of older guns....so I am not jonesing for new crap.