Ruger #1 picatinny rail - Evolution Gun Works HD Picatinny Scope Mount, Ruger

The rail itself is a quality made item. This is going on a brand new rifle that I bought in about 1987. Apparently, the profile of the rifle, where the barrel goes into the receiver, changed at some later date on #1's. Mine is beveled up the sides and square for about 5/8" on the top. The radius on the bottom rear of the rail hits this square shoulder before the rail can seat. You either have to do a lot of filing or take it to a machine shop to be milled. Mine is at a machine shop now. This is a 270 Winchester with a 26" barrel. Using the stock rail and Ruger rings you can only use about a 6 power scope. My Leupold goes up to 14 power and you have to go into contortions to get close enough to get a full picture. A Leupold AR one piece base and 30mm rings has a 2.5 inch offset. Turn it around backwards from the way you would put it on an AR and the scope can be moved back to where you can get a full picture. Walla!!!