Thanks Scattergunner, This is why I am in need of scope rails, a happy story. I was looking for a Tracker I and wanted to build up a smoothbore deer shotgun with sights. After looking around I finally screwed up my courage enough to go to my local gunsmith and to try to beg and plead him to drill and tap both my 24" smoothbore 12 gauge barrel with screw in chokes and my Tracker II 12 gauge barrel for scope rails. Knowing he has in the past turned guys down for similar procedures off I went, barrels in hand but without much hope in my heart. After a time with a dial micrometer and looking over my barrels and the H&R scope rail I had taken off one of my Sportsters and brought along with the 6/48 screws that it comes with, measuring everything again, looking off into the distance, measuring everything again, we went out for a cup of coffee. When we got back he measured everything again, said me would probably have to file a couple of thousands off the bottom of the mounting screws and that he would call me when they were ready!!! Also I am instructed to mount the scope rails with a high shear epoxy in addition to the screws, he is not worried about chamber strength but more so of the scope shearing off. Mounted correctly it is more than adequate and safe. Boy am I happy!!! Now I need 3 more (long/Ultra) scope rails to complete my projects. The last rail will go onto, hold your breath! a .35 Whelen barrel I got from another Forum member, Thanks Montanan!!. My other project is my short barreled .280 Remington woods rifle, Thanks Lik2hunt!!, ...Like is good, because of God, and don't forget it....<><.... :grin: (by the way my gunsmith is a great guy, a Christian and very active in his church!!)