I've always felt that even a 5 shot snubnose would be sufficient for the vast majority of self-defense situations that the armed Civilian might encounter and still feel that way. However,there are documented accounts where 5, 10 or even 20 shots were not enough.One case in particular stands out to me and that is the case of Police Officer Peter Soulis who had to shoot a wanted murderer 22 times with his .40 caliber Glock model 22. Seventeen of the Officer's shots hit Center Mass and the suspect lived for another 4 minutes even after the last shot was fired.It goes to show that a handgun bullet is indeed no death ray and shot placement is a key factor in ending armed conflicts and perhaps Officer Soulis should have made a head shot at some point. The autopsy revealed that the suspect was not on any kind of drugs and had only a little alcohol in his system nor was he wearing any kind of body armor.
This case is indeed exceptional,but is a possibility as there are other cases of assailants taking multiple gunshots and still continue to attack.It's incidents like this that the high round proponents point to verify the need to carry massive amounts of ammunition.Will a J-Frame Snubnose be enough? Maybe, maybe not since it's hard to predict specific scenario's. Statistics show us that it will be most of the time,but there is still those odd cases of bad guys taking multiple slugs even from 9mm's,.40 's & .45 ACPs and keep on going. Do a threat assessment about your specific geography anf type of attack your likely to face. If your in an urban are overrun with gangs then a high cap autoloader might be a better idea since the likelihood of facing multiple armed assailants is higher than the guy a small Midwest town.I myself see the threat of multiple home invaders a real possibility, so I keep my 33 Round Glocks within easy reach as is my AR-15 and 870 shotgun.
The Peter Soulis Incident http://www.lawofficer.com/news-and-articles/articles/lom/0412/the_peter_soulis_incident.html
Is the .38 Snub enough? by Mas Ayoob http://findarticles.com/p/articles/mi_m0BTT/is_149_24/ai_65910638/
The snubnose vs multiple attackers http://snubtraining.com/blog