It slides on tight. You take a wooden block and tap it on with a hammer. He provides screws and it has holes with threads so that you can have your action drilled and tapped. I have not mounted mine yet. I'm thinking about using Epoxy to hold mine in place, it's a good chance it would stay in place by just the tight dovetail fit unless you have a muzzle brake
. If you have a muzzle brake better either screw it on or Epoxy it on. I had mine on but removed it because I'm wanting to use the Leupold QRW low 30mm rings and the scope turret housing is about .015 to big to fit without bottoming out on the high points of the base. I'm wanting to machine .015-.020 off four of the islands to clear using the low ring. I think he "Richard Near" still have these in inventory in Stainless Steel. The cost is $159.00 plus shipping.