What is sufficient ammo? Well if you have room in your closet for your clothes you don’t have enough ammunition, LOL
An older person should have 100 rounds per gun? There must be a whole lot of old people living in my house. You need a sufficient amount ammunition to be able to continue training while the supply has dried up. As it has now. Obviously you need jacketed ammo for training and self-defense ammo for the rest.
Also, I think it prudent to have more ammo than you think you might need because you could very well need to supply someone else. Which is why an extra gun or two above your own needs is a good idea.
Again, one of my big concerns is that the normal people not going to become proactive until it is too late to do other than defend ourselves. It is the nature of honest, law-abiding, good people to hold off in the hopes that it will not be necessary. And unfortunately that tends to cause us to wait too long.
“You need a sufficient amount ammunition to be able to continue training while the supply has dried up.”
I certainly agree with that part. If a person has more guns than he really needs, the scenario crops up where one forgets the idiosyncrasies of each weapon, and when needed may not hit the target.
In other words, they need to be occasionally fired to stay familiar with that particular weapon, and that occasional use uses up lots ammo.
Tonight I will be practicing with a favorite revolver, probably use up 30 rounds or so of various types.