Re: .22 rifle vs. .38 handgun
The energy numbers for either cartridge, regardless of barrel length, are so far below the threshold of real "knockdown" power (as in centerfire rifle energy levels) that figures and numbers won't reflect much useful info.
Which is heavier....a ton of feathers or a ton of bricks?
I'd reckon a good .22 hollowpoint like a CCI Stinger from a 20" barrel would give a .38 Spl lead round nose or target wadcutter a serious run for its money.
But a quality .38 Spl hollowpoint like those used by Hornady, Federal, and Remington is going to much more often have more terminal effect than anything a .22 LR is likely to produce.
It's just a matter of frontal cross section and mass at the velocities the two bullets in question strike at....both of which the .38 Spl is superior in, even more so once penetration and expansion are accounted for.
For a .22 LR bullet to achieve clearly better terminal ballistics than a .38 Spl, the .22 bullet will need to be moving way faster, say another 600-1,000 fps, and then would need a better built bullet than anything in a .22 rimfire to hold its mass inside the tissues it must penetrate.
Some people still claim that .22 LR bullets bounce inside a person like a pinball or something. It's an old myth to justify using the tiny cartridge for self-defense. In reality though, no bullet...not rifle or handgun, has enough time for a bullet to do more than one 180 degree flip and/or at most a near 90 degree turn over several inches before the bullet either comes to rest or exits the body. (A bullet flipping 180 degrees is the result of the base of a round nose our pointed bullet having more mass/weight than the front, so as the bullet rapidly slows the back may become the front. But once the base of the bullet, the heavy end, is in front it stays that way until it stops or exits.)
At any rate...I'd not want to be in front of a .22 rifle or .38 snubby if the shooter can hit center mass.
Never say die!
"A nation who forgets its defenders is soon forgotten itself."
"A good shot must necessarily be a good man since the essence of good marksmanship is self-control and self-control is the essential quality of a good man." – Theodore Roosevelt