The new Model 41 barrels are/were drilled and tapped for scope mounts. I believe I used a Weaver type mounts but forget the manufacturer. I used a Tasco Gig Dot Pro Point red dot sight on mine (ca 10 inch dot). It worked well for me for bullseye pistol; matches. I sold the 41 many years ago and replaced it with a Pardini SP but still use that Tasco red dot sight.