I own several makes of BOA rifles. Remington, Winchester, Browning, Sako, Tikka, and Kimber. I would say that all of them shoot 1MOA or better with at least one kind of hunting factory load. As such, I cannot say which make is the most inaccurate from my own rifles.
I know that there are those who have had horrible accuracy experiences with the Remchesters. Like I said, all of mine are shooters. Am I just lucky? I don't know, but at the same time I cannot dismiss what other members on this site have experienced.
I have never owned any Rugers, probably not for any particular reason other than I have never really warmed up to them. I have, however, shot some Rugers, namely the 77. Some were accurate, while others were not. I my LIMITED experience with Rugers, I have found them to be generally less accurate than my other rifles. Again, this is not to say that Rugers have consistently bad accuracy problems.
Zachary