Great rifles for hunting, and that's about it. I have a 300wm M77 as my primary hunting rifle, and have it dialed under 1/2 moa. If youre planing on building an sort of "tactical" rifle off of it forget about it. If youre a fan of the Mauser type actions, and want a tactical rifle I will suggest using a Winchester Model 70 action as parts are far more available. But nothing will touch a Remington in the aftermarket department.
I personally have had horrible luck with rugger m77's I load for my friends and i cant get it to shoot less than 3 moa with any powder or bullet combination i have tried. I have had awesome luck with winchesters and savages.
I've had several Ruger hunting rifles and have had zero problems with them, but for aftermarket/tactical stuff I would go Savage or Rem. I even did a couple builds on Rugers that turned out well but they are not as easy to work on as the Rem or Savage. If your gonna buy factory and go out and shoot nuthin wrong the Ruger.