Read thru this thread and the referenced threads within it, it may help you.

http://www.huntingnet.com/forum/blac...ening-day.html

My Omega Z5 stock does allow movement back and forth between breech and muzzle, but as Sabotloader suggested in the thread, insert the screws into the lugs to start them, put the Omega on it buttstock end so that the action sits all the way back in the stock, and then tighten the screws. Put the same amount of tension on the screws each time you are putting the action back on the stock. I don't have a way to measure foot pounds, so I just use a witness mark on the stock and tighten to the mark each time (you gotta put the same screws in the same holes though).

I didn't have any issues with my stock (no polish marks), so my accuracy issues were not related to that and have since been sorted out...to an extent. Are you having accuracy problems?