I'm going to jump in here real quick and say that Ruger must be having a QC issue due to the demand of the RPR's, and their success in making a rifle that people actually want. I have been recommending the RPR for those that are just getting into LR shooting and PRS style matches. As such one person that did this asked if I could meet him at the range as he was having an issue getting it zero'ed...
Long story, short; the receiver was machined so far out of spec that with a Gen II Razor on top, we ran out of left windage and were still 4 Mils (yes, a full 4.0 mils) off at 100 yards. This is with ARC M-10 rings, so I knew the rings were good, and the scope was not likely the issue either.
That was the bad, now the good. Ruger responded, and had him ship it back, confirmed that the rifle was completely out of spec, and that they would be sending him a replacement rifle. No fuss, no hassle, just a "Hey, our bad, this thing is hosed, we'll send you another one".
Of course, now he has to wait another 10 days, and pay another processing fee (yea for Kalifornistan).
RPR's (IMHO) are a good, no frills design with a lot of thought behind them. That being said, it would appear that demand is causing some rifles to slip through proper QC. I'm not bashing Ruger per se, just advising everyone to look over their RPR's when they're buying these days, as I think there may be a bad lot of receivers that got through the QC process...
JME, YMMV...