You have to have a place for the lug or screw of the trigger guard. That means that the ramrod hole must stop at the breech end of the barrel. Usually, it must stop at the face of the breech plug(about 1/2" forward of the breech). Stopping at the breech plug face is probably best as that gives you a ramrod exactly the length of the bore. That means when inserted in an empty bore, the ramrod ferrule tip is even with the muzzle. That is the easiest way to tell if the gun is unloaded. Loaded, the ramrod would usually stick out the length of the threaded ferrule or a little more. That is sufficient to use it. For cleaning you screw on a wiper that will extend the rod a few inches. This is all my opinion, of course.