We often hear, or have heard, about various gun control laws — bans on concealed carry, restrictive carry licensing schemes, bans on gun possession by felons or violent misdemeanants, bans on gun possession by people who are the targets of restraining orders, waiting periods for purchases, and so on. But I'm looking for gun control laws that are less talked about, the sorts of laws that even people who follow gun debates in some measure might say "Huh, I'd never thought of that one."
Naturally, the judgment about which laws are little-discussed is likely to be impressionistic, but let me offer three examples. First, some states entirely ban gun possession by noncitizens; I haven't heard that discussed often, though some such state laws have been struck down by courts. Second, some states ban handgun possession — though not long gun possession — by 18-to-20-year-olds, and Illinois seems to seriously limit even long gun possession by 18-to-20-year-olds, though a note from your parent (if he isn't himself a felon, a nonresident alien, and so on) might get you out of that constraint.
Third, some states, including my own California, neither entirely ban open carrying in most public places nor entirely allow it (as other states are well known to do), but rather allow it only if the gun is unloaded. That means you can carry a gun visibly strapped to your hip and a magazine visibly strapped to the other hip, and load the gun for immediate self-defense if you have a couple of seconds, but you can't have the magazine in the gun. (This is how I read the statute, especially Cal. Penal Code § 12031(g), but I'm not a specialist; don't actually act on my casual reading if your liberty depends on it!) To be sure, you might attract untoward attention by such open carrying, but the law technically allows it, so long as no rounds are actually in the weapon.
So these are some examples; do you have more? Again, please avoid the gun control laws that are often talked about in the media — I know about them already, and so do most of our readers. Also, more details are always better; if you have a citation or a URL to such a statute, that would be great, and if you just have a hazy recollection, it would be very helpful if you could clear it up a bit.
Finally, city and county ordinances, as well as administrative regulations, are especially likely to be missed by researchers, including by me. If you have some pointers to surprising local or administrative gun controls, I'd especially love to see them.
UPDATE: I originally said that in California you could carry an unconcealed unloaded gun, and a magazine in your pocket, but Gene Hoffman kindly pointed out that People v. Hale, 43 Cal. App. 3d 353 (1974), suggests that a gun may be treated as concealed if its magazine is concealed. I'm not sure that's a proper interpretation of the statute, but it does still seem to be a binding precedent, so that's what California law appears to be. Many thanks to Gene for the correction.