Yes it is on my rifle, a custom I built on a 1908 DWM in 7x57. I had the bases made to except the Ruger high rings ( I was origionally going to use a NECG bridge aperture) We ground off the humps and used a set of Warne levers. I find my general hunting load (plain 150gn corelokt's) and a serious load ( 160gn Woodleigh) only have a 1/2in elevation difference so the sight regulated for one works with the other at the same setting. I had the rear of my cocking piece turned down and an off set collar sweated on to allow the sight the be dovetailed in as low as possible to get clearance over the top when it is wound down and the scope installed which I would only do if ranges were over 200 or so. I have a 8in x 8in wearalloy plate that is hard to miss off hand.While it may not matter to anyone else I feel so much better about making a shot with this aperture sight than I ever could with a scope and a conection to the riflemen of yesteryear.

Von Gruff.