PocketMan,
Actually, the answer to your question is a qualified MAYBE.
Some of these guns are pretty sensitive to changes in the mass of the hammer. I've seen several cases where J-frames so modified would no longer reliably ignite one or more types of ammo.
The fix for that, though, is also pretty simple, a more powerful mainspring to give the hammer more speed.
If you DO decide to do this to your gun, run at least 100 rounds of your favorite carry ammo through it BEFORE you start relying on it.
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Beware the man with the S&W .357 Mag.
Chances are he knows how to use it.