Maybe. Issues with J-frame rimfires is that they come from the factory with a heavier-than-normal mainspring to ensure ignition of t he rimfire primers. Now, I know a number of people who've done trigger jobs, and some who've installed normal-weight mainsprings: they report that everything works fine.
Well, these are trustworthy people, so I'm sure that's so - for them . . . so far. But I have to wonder what interest the S&W engineers had in installing a heavier-than-normal spring in the first place. It
wasn't because S&W wanted to make the trigger pulls on these rimfire Js more unpleasant than the triggers on their standard Js . . . I'm pretty sure of that.
So, I'm of the opinion that the heavier mainspring is a good idea.
I can report that my Model 34 was
not an accurate .22 LR for me or any other adult (a 10-yr-old did better with it than any of us) - but that might have been the combo of the heavier mainspring and the small backstrap-to-triggerface distance on a J-frame. Perhaps putting enclosed backstrap stocks on the thing would have made it more accurate, but you're definitely not anywhere near the league of a Model 17 with a J-22.
As far as .22 Mag out of a handgun goes, I have a Bowen-converted Bearcat that has the appropriate barrel for .22 Mag (one of the post-'93 barrels originally intended for the conversion Bearcat before they pulled the .22 Mag cylinders due to people fanning them). I find that the (4") gun gives dramatically increased velocities from when it was a .22 LR (I get over 1400 fps with several 40g-gr loadings), but that it's
profoundly ammo specific: my gun likes Winchesters and groups decently with them, but any CCI/Federal/Remington or Fiocchi just
patterns at 10 yards - and many of those bullets keyhole.
Any rimfire .22 revolver is going to have ammo that it likes better than other ammo, but I've never seen such a rejection of ammo by a gun like from this Bearcat. Feed it what it likes, it's fine. Otherwise, forget it.
Now, what are your velocities going to be like from a 1 7/8" tube? 40-grains at 1050 fps? That's what Google searches lead me to believe . . . compare that to what a Velocitor will do from a similar length .22 LR revolver. Because .22 Mag ammo is not cheap.
Anyhow, just some thoughts for you to consider. I like the .22 Mag cartridge a lot, FWIW, and like the idea of the 351 quite a bit for some limited uses.
Oh, and welcome to the forum, dude!
