It may be drilled and tapped from the bottom. The problem I see with this mount is that it's mounted towards of the front of the gun, with the weight of the scope towards the back. So it's subject to more upward recoil force. I would expect a seesaw type of effect during recoil. Maybe even causing more front flip up of the gun. Your gun being a .22 shouldn't have much front flip at all, but i think a regular .45 would have it.