What Black Tail Hunter is writing, comes almost to the truth. You got most likely a clearance problem by using the "wrong" equipment concerning rail and may be also the ring - mounts. I've just read an article in a swedish gun magazine (vapen) where they talk about semi - custom build ups of Sako and Tikka rifles. They also use rails under the different projects, but always the originals made
by Sako itself
Ask a competent dealer in the USA, or directly Beretta's customer service about this. Further on they are using mounts made by Spuhr
(top quality and expensive). You might also use original optilocks for that purpose to get the right clearance.
Hope I could help you.