Have a Marlin 39A that needs a rear sight. I ordered a Williams #70808 with the tang on the front and a single hole to mount on the top. Doesn't seem to fit my gun- and the mounting screw is too big. They also have a side mount sight #1256.

anyone able to help me out on which one is he right one?

thanks
chuck

What year is you 39a?
I have a Williams FP 39 with added extended elevation target knob on a 1968 39as and a 94/36 FP/tk on a 1958 Mountie.

Don't forget the knobed gib lock screw.

Also if you want to install the extended target screw you need to first get a FP/tk, Fool Proof with target knobs.
The regular FP sights don't allow for the extended screw.

Williams thread hijack. Does anyone have a good trick to snug up a loose "aperture holder" on Williams fp rear sights? Only one of ours is snug on the windage screw. The weight of the merit disk probably keeps them in the same position shot to shot but that seems a little sketchy.