On one of mine all I had to do was use the cylindrical stone in the Dremel to 'dish out' the inside top of the hammer to clear (thats where the hammer should first contact anyway if things a straight & true). I should also mention that the different scope rails have different installled heights where the rings seat, so it will affect your scope height. IIRC the H&R rail I have is the thickest. A combination of certain rings and rails can get you to the sweet spot. I quit with the hammer extension for my use, though I can see that with gloves on you might need one.