I own two different .22LR/.22Mag factory convertible double-cylinder SA revolvers, one Ruger Single Six and one NAA MiniMaster. Both shoot extremely well with both cylinders.
What I recommend is, slug the bore of your barrel and then measure it, and contact a good gunsmith who can modify your current cylinder to .22Mag. The gunsmith can tell you how well your barrel bore diameter is liable to shoot the Mags, and what it'll cost to bore out the cylinder (the only real difference). By modifying the original cylinder, you won't have to worry about first scoring a new cylinder and then timing/fitting it to your gun. It *might* be cheaper to do new parts, but I sorta doubt it.
Jim Stroh at Alpha Precision does a lot of cylinder mods and related work...I'd be willing to bet he could do it or advise you professionally:
http://www.alphaprecisioninc.com
To slug the barrel, get ahold of a lead bullet and shove it slowly clean through the barrel (NOT the cylinder too) with a wooden rod, aluminum cleaning rod or similar. The Remington Yellowjacket has a long skinny nose that's real easy to grab with a pair of pliers so you can pull it out of the shell gently. You don't want to put your pliers on the part of the bullet that will be contacting the barrel bore, which makes the Yellowjacket one of the easiest to pull without too much distortion.
Now, I forget which bore size is optimum with .22Magnums versus LR. I *think* the LR likes a .223 bore, while Mag likes .224. But they're really cross-compatible within reason. Slug yours, measure it with a micrometer, then get pro advice.
Overall, I think if your model gun also comes in a Magnum flavor and is otherwise sound, there's no reason not to convert it to Magnum. From an 8"+ tube, you're gonna get some *serious* velocity from the CCI MaxiMag +Vs. From a 4" tube they can do 1,400fps...1,200fps from a 1.5" tube, so at that progression...1,600fps is the *minimum* you can expect...if you hit 1,700, you're in .38spl territory in terms of energy levels (193ft/lbs)
.
That's personal defense grade
. I sure as hell wouldn't want to be hit with something like that.
Jim