What would you choose?

The .38.
No contest.

As much as I love my rimfire pistols and revolvers, I would definite go with the 38 for CCW. Centerfire ammunition is always more reliable than rimfire ammunition

.38
I would choose it even if I had to choose the ammo you mentioned.
But I would use Buffalo Bore 158 grain SWC hollow points if I carried a .38 Special, assuming I could find them of course.

I'd take the .38 too, but I wouldn't carry either of those as a daily carry.

If it had to be a .38 revolver, one of the 2"- 4" K frames in a proper holster would be my choice.

The .38, but with 158 gr hardcast SWC. I wouldn't feel at too great a disadvantage with the .22 mag though.

You left out the velocities but just like Armored farmer, I'm going with the 38 snub (5 x 130 = 650 grains of lead versus 9 x 40 = 360 grains of lead). Since you didn't specify the number of threats, I'll go ahead and assume just 1. Since no other special circumstances were mentioned, I'll assume there are none. So for just man-about-town conceal carry, I'll take the 38 snub.

I'd opt for the .38 Snub...carried a LCR357 loaded with .38Spcl for years.

The 38 snub for sure

38 for primer reliability, even though I never had a 22 mag failure in a revolver.

If you need more than 5 rounds of 38 the three extra 22 mags wouldn't make a difference. For me a 38 or 9mm snubbie, (I Have both) is a minimum needed. If it weren't so hard to find ammo a 327 Federal magnum snubbie to me is a really good way to go. I love 22 mag and have several handguns and rifles in that cartridge and not pooh pooing it all, just not the same.

Have to go with the .38 snubby over a J frame .22 Magnum with a 4" barrel.

My two favorites:

If I was limited to a 22WMR handgun only, I would carry a Kel-Tec PRM30 over a 9 shot revolver. Like "Johny Reb" said load it up on Sunday and shoot all week.

I'd go with the snub but I'd prefer 158gr LSWC. The .22Mag wouldn't be terrible either but I'd go with the thirty-eight.

.38 Special snub nose hands down like everyone else is pretty much stating. Not trying to hijack the thread but Paul Harrell has an interesting video about standard pressure ammo that I found informative.

The 38 snubby, I carry one frequently.

No hesitation on this one; the .38 with the HST loads makes for a very effective combo.

Stay safe.

38 without a second thought

I vote for the 38 also. My reasoning much the same as the others. But I'll add, since I reload 38, ammo availability isn't an issue compared to a purchase only round.

The 22 mag.
Larger capacity
Much quicker follow up
I enjoy 22 mags a lot more than 38s
Cheaper ammo
The psychological effect of the 3 ft fireballs that .22 mags produce

If funds are available, 6 shot Kimber K6S. Or 6 shot LCR 327.

I have a mixed of the two, the SW351c. And I carry it daily, in my front pocket in an Alabama Holster. Very light, very accurate. Gets beat up and scratched from carry. Has killed several rats in the barn, and will work on anything in Ohio that wants to do me harm.

Of the two choices you listed, the 38 snubbie would be my choice. Can’t beat the Airweights in any caliber, but standard pressure 38 158gr SP or LSWC will get you through if you do your job and the low recoil helps with that. And the snubbie is easier to carry. You are pretty much stuck with a belt holster for the 4” 22mag. And it’s easy to leave your EDC in the truck or at home if it’s not convenient enough for you to carry.

Of the ammo you picked for the 38, the HSTs have shown to be what the experts want to look like when shot in gelatin. And this is not sarcasm, it’s science. I just do not trust HPs in very short barrels, I like solid penetrating bullets in them. I have seen what they do to blood, bone, fat, and skin and I made my choice. I carry super hard casted 148gr WCs I casted myself, with a max powder load behind them in my 642/637/36. It’s my practice and carry load for any 38/357 pistol I have.

On 22mag ammo, I really don’t like HPs. I don’t worry about over penetrating with either calibers, because I just haven’t seen them to have enough energy after exiting a head even. The short barrel of the pistol doesn’t really give the 22mag enough to work up a full head of steam. With that said, the first two rounds in my 351c is the GDs. They will vaporizer a rat cocky enough to stand up on a straw bale eating feed. I have used the Hornady CD as well. I like them over rat shot. I just want a solid bullet penetrating as much as it can before running out of energy. The other five rounds, it’s a seven shooter, are CCI solid points.

One thing I will say about rimfire ammo, I’m not a fan due it it having a lot of failure to fire issues, or duds. Usually takes more than one strike to go off. But I do not see that is an issue with 22mags. I can’t remember the last time I had a 22mag not go bang.

Lefty

My two j frames that get the most use and abuse.

View attachment 1002470View attachment 1002471

Since it's a self defence question, ask yourself these questions.

1, if I have to stick my gun in someone's face and that causes them to desist, which bore size do you want them to see? Which will be more effective?

2. If I have to shoot them but I will only use 1 round, which caliber would be better. If it's 2 rounds, which caliber would be better?

i love rimfire revolvers, but got rid of a ruger lcr 22wmr and replaced it with a ruger lcr 22lr for a sometimes ccw. 22wmr out of a short barrel was way too much flashbang for too little result, even with handgun specific ammo. i was unable to keep shots on target. the lcr 22lr is superb.

i also like an airweight s&w 642 38sp snubbie for a ccw, but only shooting softer wadcutters.

of these two, i get much more (necessary) practice with the lcr 22lr, and 8 consistently accurate center mass 22lr hits would likely serve my humble suburban needs. if i were to be in the outdoors awhile a ruger single six loaded with 22wmr, and packing the 22lr cylinder, would be my choice.