An action with nine locking lugs is no different if it's a Deluxe MarkV,Synthetic,Accumark,or UltraLW.The actions are all the same size.If you have a standaed caliber like 270,30-06,223,or a 240 Weatherby mag you have a Lightweight with 6 locking lugs.These are a little difference in size (smaller)than the nine lug action.