however much you, and your finances are happy with. only you know how much you shoot. a person who shoots every week will burn up a lot more ammo than one who shoots 3 or 4 times a year. there is no sense in having 10,000 rounds of 45 acp in your basement if it will sit there until your great grand child is born (unless you are already 70, and you shoot everyday). but, you should have enough to get you through a bad economic time of say 6 months to 1 year. if things get so bad that you can not buy ammo for 1 year, you have a lot more to worry about than feeding your shooting habit! also, rotate all ammo you have/buy. unless there is something in your inventory that can not be replaced, and you are specificly saving it. that way, your ammo will not get more that 2-5 years old.