Thanks a lot for the suggestions! I need all the help I can get.
I don't think the base could be on backwards, as the front and rear mounting surfaces have different radii (Sp.?), with the front being much more round. The screw spacing is different as well.
My memory tells me I ordered a 0 MOA model, but my memory is even worse than my personal hygeine, so I will check up on that to be sure.
I recently read on this board or possibly another that this problem is not rare, and it stems from Remington's manufacturing practices. Some guy, who may or may not know what he was talking about, said something to the effect that the round, forward part of the receiver is mostly finished or dimensioned on a lathe, but the flatter mounting surface at the rear of the receiver gets more hand finishing. He said this sometimes results in uneven mounting surfaces, and helps to support the shim market!
It looks like Brownell's sells a few of those little guys, with correct screw spacings for the front or rear of the mount.
While I was wandering aimlessly around the garage this morning I stumbled across an EGW base that will fit that rifle. After the initial lust for the new rifle wears off, I may install that base and see if the fit is any better, to see if the base is indeed at fault.
On the other hand, if this thing continues to print under 0.5 MOA, I may just learn to love it as it is, like a homely woman who can curl my toenails, or an obnoxious neighbor who knows how to fix cars and solve plumbing emergencies. After all, I have a few minor, very very very small, very minor faults myself. Hard as that may be to believe.