I am building a "drop in" barrel for my TC Seneca and am trying to determine if their is an optimum forward vs. rearward location for the rear sight? I am planning on installing the type of adjustable rear sight which is elevated with a screw which simply pushes the rear sight up by screwing the screw thru the sight and against the top of the barrel. My concern there is that the screw may "self adjust" from recoil. Any suggestions on how to bind the threads on the screw a bit? Know your target. Hank