On what should one base the number of rounds one prefers to carry? One's gut? One's experience? Statistics?
Recent lethal-force statistics suggest the current avg is 8 rounds per incident [1].
The old avg of 2-3 rnds has increased over the years; a bit because of the shift from revolvers to autos, but more significantly due to changes in handgun tactics.
The incidence of situations involving multiple attackers is also increasing. Should that factor into one's calculus? I think so.
Can one get by with less? Maybe? Who knows? It depends.
As you decrease the number of rounds carried, the probability that you won't have enough (if a situation arises) increases. They are inversely related.
If friends ask me, for the above reasons I suggest they consider something with a payload of at least 8 rounds if they can. Most end up with something on the order of 15 rounds (and carry a spare mag).
You pays your money and you takes your chances.
[1] - John Farnam - Enough Ammunition
I think it's really up to the individual and their belief or comfort level in how they feel they need to be prepared to protect themselves!
When I was single...I carried a 5-shot, SP101 .357 for years very comfortably! I never felt I needed anything more...ever!
But as I've grown older...and my experience has changed, improved, been re-considered, etc...I'm now a big believer in the .45 acp cartridge! I've gained an appreciation for the 'bigger-is-better' approach...and am making the transition to .45! As always, I'll probably end up with more than one...but they'll be guns I become very familiar with and develop the capability to shoot well before I would consider carrying them!
One other issue is the changes in how crimes are being carried out...and the greater number of incidents's involving larger numbers of groups committing crimes together! Being aware of one's surroundings and definitely knowing when to get the heck out of Dodge can go a long way to preventing being a victim of crime!
Stay alert...even though you may not be able to prevent the crime from occuring, having a split-second to prepare to defend yourself can go a long way toward not being a victim! Your mind is still your best defense and/or weapon!