A gun is a gun, and it's better than .22LR from an itty bitty barrel like that, but I was never strongly convinced of .22WMR from pistol length barrels except for handgun hunting smaller animals.
You'd definitely be able to threaten and deter an assailant with one, and injure him too, maybe even fatally, but I don't love the odds.

If I was gonna carry a small revolver, I'd want it to be a .38 Special.
If I was gonna carry a .22 caliber handgun for defense, it would be one of those REALLY tiny Mini Revolvers to make it worth meek penetration, something that I could conceal in my asscrack or in my mouth or something.
Would never be my first choice though.

>>64003817
I think some of those Kahr 9mm pistols can hold 8 or 9 rds and they are double-action. I don't know if they're still in business though.