I often carry my 317 Airlite (8 rounds of CCI) or my 351 (7 rounds of hot .22 mags) roaming around the farm/woods. Would not be my first choice re self-defense, but clearly capable of killing someone. Most of the time, just being armed and being able to shoot is all the deterrent you need. haven't run into any Meth-crazed carjackers (yet) but feel fully capable of engaging them if that is what I was carrying at the time. As we all know, it is all about shot placement. My preferred weapons are the Model 327 PD or my Kimber TLE. Both with eight shots.
Also, sometimes, all you need is a "mobility" kill -- the majority of bad guys who take a couple of hits (IMHO) from a .22 LR or .22 mag will be out of the fight -- one to the face/head, two center of mass, one in lower abdomen -- your average bad guy will be in full retreat and not feeling so good , hurting in several different areas. Psychologically, bullet hits to different parts of the body really distracts the bad guy -- . Also, the new .32 auto rounds with 60 to 71 grain PD bullets will do a number on someone. I have aTomcat .32 auto with an extra clip as a BUG, very efficient at 10-20 yard fights. And most gunfights occur at 5 - 15 yards according to articles/analyses I have seen.