I have the same thing on my pursuit's hammer(scope extention) and only had to remove the sight and not the base but with low mounts I had to remove the sight and the scope was actually putting pressure down on the hammer and I couldn't even cock the hammer, so I went to higher mounts as I metioned above and I still had to remove the sight but the hammer had plenty of clearence. Then after all that I took the scope of and just went with open sights.