Just to make things a little more complicated....
If you are only wanting function and don't care about the looks of the rail, take a look at burris signature zee rings. I use them on my 223 and 22. They have plastic inserts, that provide the can't so you can decide the amount of MOA you want. I am a real big fan of them. They also help you get the scope lower to the bore, than rails generally allow. I bought mine from optics planet on sale, and everything all told was like $30