I've have decided to move back to my Thompson encore for turkey. While I was away from it I fell in love with a red dot. I'd like to mount it, on the Thompson. I can see two holes pre-drilled in the barrel, but all pic rails seem to have 6 or 4 holes, are there two more under the sight I can access if I remove the sight? Or, do I need to have it drilled/tapped for additional screws to mount the rail? Thank you for your consideration and replies.
Maineiac