I have damaged my front sight ramp on my 336CS. I ordered what I thought was the right replacement from Numrich, but upon installation it does fit. The screw holes are the proper distance apart , but it wont sit far enough back on the barrel to screw down. It hits the barrel band. And I don't see where there is another part number. Am I missing something? Is there a different style thats just not listed. The number I received is 407200B. Any Ideas? Thanks