S&W 442 or other J-frame as sole self-defense weapon.

[johnnywitt]

I wouldn't want to go up against an expert shooter with an 8 shot .22 J Frame that could put 2 head shots in me in less than a second.
A vest will defeat most pistol rounds and most guys are going to shoot for CM right into the vest. How about a Guy that's only going for close range head shots with the .22.
Jim Brady would tell you that usually doesn't end well.
It's also a huge tactical advantage IMO to front pocket carry a J Frame for CCW type defensive situations. I can have my hand on my gun before the other Guy can even start to peel back his cover garment.
J Frames aren't sexy or glamorous and are considered too old school, but they still work better than anything else in some roles IMHO.