The topbreak design is relatively weak and the 9 mm is a high pressure round (35,000 psi), similar to the .357 Magnum. I don't think this one would fly, although the revolver might fly apart!
Didn't Detonics make a .44 top-break 25 or so years ago? The S&W #3 was a pretty solid gun in it's time. it would seem like a .38 spl. would be doable w/ todays metallurgy... maybe part titanium or polymer? I've thought this would be a great idea for half of my life.