DNZ's Game Reaper is precision machined from a solid block of top-grade billet aluminum, and is custom made to fit each type of firearm and align perfectly with your rifle receiver with no moving parts between the firearm and the scope. The Game Reaper absorbs shock and withstands temperature extremes better than steel mounts. All BAR actions use the same mount. This mount also fits the long action BLR. Same mount used on a Benelli R1 rifle. Base screws are 6-48 X 1/4 long and ring screws are 6-40 X 5/8. Both use 7/64 Allen wrench.