One of my 60s was hard to open. (Pawn shop find). I did three things before it became satisfactory. Cleaned crud from behind the thumb latch, internally. Polished the bevil on the end of the ejector rod. Stoned and polished the ejector rod plunger/retainer underneath the barrel. It had really sharp angles. It is still the most stubborn of my J Frames, but it works with the described click/snap.

Luck,

Jack