Xs big dot for j frame & sp101 - XS Sight Systems Dot Tritium Sight

This is the best sight that I have found for the J Frame and SP101 snubby revolvers. Visible night or day. Need to stone a little off each side so that it fits into the groove, then drill through existing holes (and the sight in the middle) with a 1/8" drill bit (a Dremel works). Stones and drill bits available at hardware store or on Amazon - you'll also need a 1/16" punch for the roll pin.

Takes a little skill to install, but any competent DIY person will manage it. YouTube videos show you how.

Should last a lifetime, though the tritium part will be dim after 10yrs or so.

Follow the aiming instructions provided and you can shoot surprisingly accurately at any practical distance.