I don't mean any shade to the OP of this thread, and I think .22 magnum in handguns has its uses. But I always recommend that anyone considering a .22 magnum handgun take a look at
www.ballisticsbytheinch.com to understand how .22 magnum is affected by barrel length. In short, from smaller pistols, .22 magnum does not come close to the 40 grains at 1800+ fps that made the round so respected in rifles.
From a 3" barrel, no .22 magnum rounds reach the 40 grains at 1250 fps that high velocity .22 long rifle will deliver from a rifle barrel. .22 magnum still outperforms .22 lr from a similar sized pistol, but the performance is not great. You also get a surprising amount of noise and flash from .22 magnum in short barrels, so it seems more powerful than it is.
Again, I am not totally knocking .22 magnum. But from a small pistol, it should not be used for any jobs that are too big for a .22 rifle. And it is not at all similar to .22 magnum from a rifle length barrel, which has a large step more power than .22 lr.
Ballistics by the inch also shows that the round is very sensitive to barrel length. So from a 6" Single Six revolver, it picks up significant velocity, and some rounds do exceed the performance of .22 lr from a rifle. However, this is not helpful in the search for an extremely compact pistol.
Also, to the best of my knowledge, none of the recent .22 magnum rounds that are designed for short barrels actually deliver significantly better ballistics, though some of them may have projectiles that are better designed for their actual velocity.