I had mine on my gunsmithing bench for clean and lube and two screws fell out. SO I took it apart and looked for where they came from, it did not take long to figer out they were the mounting screws for the trigger mechanism so I locktighted them and put it back together.
POINT BEING they could have got lost and there would have been only the tail screw that goes into the stock on the outside; you might consider checking the trigger mechanism for looseness once in a while,if its loose pull the rails and trigger mechsnism out and tighten them I put locktight on mine so they wont come loose again. Lee