Instead of debating the endless cartridge/caliber war, I would suggest heeding all the above advice about hitting. A heavier revolver is going to be easier to make hits with, and so will a longer revolver be. While it's true that revolvers are unique in the available extreme power-to-weight ratio, the low weights, under 20 ounces, even as low as 11 ounces, are a poor choice for what we know to be effective ammunition. I think there is some consensus that 9x19mm is on the bottom end but still within what is known to be effective. Plenty of people debate the merits and trade-offs of more powerful ammo, but let's say that 9x19 isn't widely agreed upon as ineffective. Revolvers differ a little than reciprocating slide automatics in that there is nothing but their mass to slow recoil velocity. Consider what mass is needed in the revolver for you to control a round loaded to 9x19 recoil levels. You have to be real with yourself about what "control" means. For me, if I can't score hits on a 5" diameter plate at 15 yards fairly rapidly, that's not a good sign. There are lots of drills you can use to evaluate how much a gun is hindering your ability. Try a Bill Drill, Dot Torture Drill, try the FBI qualification... and many more. I would bet that you'll find you are more effective with a gun over 20 ounces, but that you will also gain significant effectiveness with a barrel 3.5" or longer.
Now you can consider going lower than 9x19 power levels to 38 Special +P, 38 Special standard, or a mid-range .32 load, but how low do you have to go to get the control level up to where you'd be with a heavier, longer gun? Why not just get the heavier and longer gun? What's preventing that?
