I don`t know what happened? The sights were right on when I touched `er off!!! One of my favorites when I miss something I shoulda hit!!!
And as I told my B.I.L. a few years back that had the very same "problem" with his sights shifting..."Always carry a wallking/shooting stick". I watched him whiff on a big doe standing broadside at 40 yards with his flintlock. He cut a stick after that and his next shot at over 60 yards put one in the boiler maker of the very same doe.
Big Al's "Take-Em" Style Silhouette Decoys Pro-Staff.