not suchas issue with Rugers, more of an issue with older dovetails on rifles......we usually looks to "see" which side has the "wear"( the blue may be worn off the edges of the slot...a good light will tell you real quick, but again, it makes no difference to us, as long as you :loosen the set screws if there are any........as said above....THAT will make a difference as well as how "firm" the gun is held in a good ,sturdy , padded vise.......