Lanza had other guns with him, though it seems he primarily used the rifle.  This is something I mentioned earlier: most of these shootings don't use "assault weapons," whether they're black rifles or not.  Lanza used an AR-15, but still had pistols with him.  Holmes had an AR-15, but he also had a shotgun and two pistols.  Virginia Tech was pistols.  Columbine was pistols and shotguns.  Charles Whitman had pistols, rifles and a shotgun.  There's always a pistol though.  There is a reason I'm trying to drive this point home.  Overall, "assault weapons" or black rifles represent a very small slice of gun crime, less than 2%.

As for magazines, the lesson from California is you have to ban possession of the magazines.  That might seem silly, but I'm trying to impress upon people that we've at times we've made some really silly gun laws, not in the sense that gun owners don't like them, but in the sense that they're almost completely ineffective.  Seriously, the high-cap mag ban in CA doesn't ban possession.  #1 rated gun control regime by the Brady Campaign.  I'm not making these points for no reason.  This also practically means coming up with a way to collect high-cap mags.  Otherwise, current owners are usually grandfathered in.  Panic buying will swell ownership in that case, but it would eventually diminish.  There are very few legal automatic weapons left in the US and they're insanely expensive, like $20k.  High capacity magazines could eventually go this way as well.

However, remember Virginia Tech.  No high-caps were used, just lots of extras.  Given this, it might also be prudent to think about limiting the total number of magazines.  This would rankle target shooters a lot, but one thing you can't really do in the heat of the moment is reload an unloaded magazine.  It's annoying to repack the same couple of mags all day at the range, but it works.

Not sure how you do the ammo limit and storage provision without home inspections.  As I understand it, this is done in at least some parts of the UK.

Hollow-point rounds are a bit misunderstood.  Yes, they are designed to deposit all their energy into the target.  Another way to put this is that they're designed to stay in the target, since no energy equals no movement.  If you're conceding firearm ownership for home defense, there's a strong argument to make in favor of hollow-point rounds because they don't travel through the target and walls, etc.  This means that hollow-points are less likely to end up in your neighbor's house when someone decides to take on a burglar or forgets to clear the chamber when they're cleaning.  It seems to me like hollow-points are sometimes conflated with armor piercing rounds, which isn't really the case.  In fact, FMJ rounds do a much better job of penetrating armor and walls, which is why the military uses them.  The larger point here is that bullets are designed for lethality, period.  There's no such thing as less lethal bullets, just bullets that keep going through stuff and bullets that stop when they hit something.  This distinction is germane.

You could bar young shooters from the range, but how about people who shoot on their own property?  How you prevent them from teaching their kids to fire semi-autos if they have them?  Powder test kids?

I think every home with a gun should have a mounted combination safe.  Key locks are too easy to circumvent.  I posted a video in a response to MM showing how easy it is to foil most key locks, even on official "gun safes."  Any of these methods could be employed by savvy teenagers.  Some of these devices have locks that are about as robust as those found on filing cabinets.

I would also potentially support a measure that says you have to purchase a qualified safe and have it installed and inspected before you're allowed to buy a gun.  However, it's worth nothing that this would make owning a firearm prohibitively expensive for someone who might have a need for protection.  That might be acceptable and it might not.  Also, locks and safes are really only good against the relatively undetermined and only if they're of sufficient quality and only if they're used religiously.  All it takes is once.  Still, it's really the minimum security that should be in place for any gun.

Trigger locks are good for keeping your four year old from using the weapon.  In my opinion, if your kid got hold of the weapon you already screwed up.  Actually, I would even raise caution against the trigger lock variety.  Many of these are just made of plastic and can be pulled off with bare hands.  They also can breed a false sense of security about where the gun can be stored when it's loaded.  Seriously, some of them just pop right off.  Cable locks that prevent the action from operating are much better, but they're no protection against thieves or anyone who has time alone with the weapon and is determined to make it work.

In CA, a felony means you lose your right to own a gun.  Not at all DUIs here are necessarily felonies.  I think you have to wait ten years and get your right to own a gun re-instated by a judge, but I might be mistaken about this.

CA also has a law that holds gun owners responsible if they let kids get their guns.  I fully support this law.  It's a no-brainer.  If you own a gun, it's your responsibility.

Since you mentioned cars: Why not mandate governors on any vehicle that's used on public roads?  Cap speed on all cars at 55 MPH.  Auto accidents kill many more people than guns every year.  Like bullets, cars get more destructive linearly as their mass increases, but more destructively exponentially as their velocity increases.  Eliminating the possibility of traveling at reckless speeds wouldn't just eliminate the need to enforce speeding laws on the highway, it would unambiguously save lives by making auto accidents less deadly.

Rachel Maddow tonight mentioned a series of single-purpose acts proposed and passed by individual Congressmen over the last decade. Taken individually they seem like pin pricks.For example one prohibited ATF from publishing statistics on gun deaths.- they could accumulate the info but not publish it.

What's worrying is that there was someone who had a plan for what they wanted to do about gun control and was quietly pursuing it