On two other forums they did a survey of how many members have actually used their guns and how many actually fired more than three shoots. Almost zero have ever used one, and just a small fraction have ever shot one especially more than three rounds.
You have to be kind of careful here.
Before I start, let me say I'm going to focus exclusively on the logic here and never mention any number of rounds that is enough/too much/too little/etc., let alone try to recommend a particular number.
Ok, with that out of the way.
It might make sense to not carry a gun at all if one assesses that the chance of needing one is too small to bother with.
But if a person assesses that the chance of needing one is sufficient to carry one, then it doesn't make sense to carry one that is likely to be insufficient for a reasonable scenario. What a person needs when they need a gun is a different problem from whether or not a person needs a gun.
That may not be immediately obvious, so here's an example. Let's say you're running an air force for a small country. You are looking at the expense of giving every one of your aircrew members a parachute and it's going to cost enough money that it's difficult to budget for.
So you decide: "The odds of them needing a parachute in peacetime is so small that I'll just have them each carry parachutes that will only safely support the weight of a person who is 100lbs or less. It will save a lot of money. Sure, all of our aircrew members are heavier than that, but it's so unlikely that they will need them in the first place there's no point in spending more."
Well, it might have made sense for you to decide that the risk of needing a parachute was so small that there was no need to carry parachutes at all. But if you're going to give them parachutes, it doesn't make sense to give them parachutes that are so small that they won't work for them. If they actually do need a parachute, they will need one that is rated for their weight--it does them little good to have a parachute that isn't going to work for them when they need it. You might as well have just saved the money entirely and not bought any parachutes at all.
That example is picked to make the point, but the same general principle applies. When you need a gun, you will need it to solve a problem. What is required to solve that problem is a function of the particular problem you are faced with, not how likely it is that you will need a gun in the first place.
Never have I seen anyone in a gunfight that actually had to use more than one magazine.
I think we would need more information to determine the usefulness of that information. At a minimum, we would need to know the following:
1. How many of the people that lost the gunfight that reality handed them would likely have prevailed if they had more ammunition?
2. How many of them used what was in the gun only because that was all they had?