These are just goals. I am hoping I get there someday. There is no need to buy anther gun if one only has a few hundred rounds of ammo. Otherwise you just have a heavy club. Buy ammo before a second gun in a caliber. Buy a second gun in the same caliber before buying another caliber. Those are my rules.
I see so many gun owners who say that their guns were lost. They are going to hide them from the enforcers of Federal Gun Laws. We also have people who brag on their stock piles of ammo? It seems we have many different ideas on what is to come over the next 4 years?
Enough to fill my mags, that's it. I don't believe anything is going to happen that would find me needing any more than that. Also always have thousands of rounds of 22lr, but thats just because the boxes I buy have more than I shoot in one session. Sometimes I've got an extra 50 of 9mm or 45acp after a range session, like now, but I don't ever feel any need or desire to keep a "stock pile".
For the past two years, every week when my wife buys groceries, she gets 100 rounds of .380, 9mm, or .40 cal. Whenever we go shooting, we buy what we shoot. I'd say we're pretty stocked up. Do I think I'll ever shoot it all? No. Do I think the world is going to end? I hope not, but if we do have any major economic collapse, I plan on trading ammo for toilet paper and food.
As for 22LR, about 5,000 rounds mixed between various types of target, subsonic and supersonic ammo. As for everything centerfire, a Dillon 650. You didn't ask about how many primers, bullets and brass so I'll say...enough.
I normally keep at least 200-300 rounds in every caliber that I own. The only issue is that I own 12 different calibers of firearms. I have found that I am purchasing more ammo in bulk now, so that 200-300 rounds have grown...... Until I go to the range