Let's accept the following premises:
1. The AWB is a load of crap. It involves weapons not involved in most of the infamous shootings of this decade. While it was internally effective (it did reduce the number of the weapons it targetted circulating), it was ineffective at its intended ultimate goal (reducing gun violence or making it less lethal - there was no reduction in the amount of gun violence during its enforcement.)
2. It's certainly arguable that it's too easy for people who wish to misuse guns to obtain them. And there's quite a bit of concern about any guns that can fire a lot of bullets in a short space of time.
3. Under the current constitution, you can't ban the vast majority of guns.
4. In the current climate, legitimate gun owners would not cooperate with any program, voluntary or otherwise, that requires they give up existing weapons, and they'd lobby hard against restrictions on what they can own.
So what we're looking for is a gesture that would satisfy the concerns of those who strongly believe (2) above, while recognizing (3) and (4), and also doing something that's not already been tried, and not already been completely discredited.
So this is where my mind is at at the moment.
In most states, there's already a set of laws about under what circumstances you can bear arms. The system in most states is:
1. Anyone can bear arms inside their own homes.
2. Anyone with a Concealed Carry Weapons Permit can bear arms outside of their own homes, as long as they keep them out of sight until needed.
The CCW system is relatively popular amongst gun owners. It's not controversial for the vast majority. Most gun owners I've met encourage other gun owners to get the permit, but they see the requirements as actually a good thing.
Permits are issued under a number of circumstances, but even in "Shall Issue" states (Shall Issue means that it's up to government to prove you're irresponsible, rather than for you to prove you're responsible) there are specific actions from those applying for a permit that encourage responsible ownership. Here in Florida, for example, there's a mandatory gun safety class that needs to be passed before you can get your CCW.
States have massive lee-way in terms of how they implement the CCW program (well, it's their program.)
My thought is this. Rather than an all-out ban on "dangerous weapons" (or worse, "scary weapons"), perhaps a better solution would be to recognize the CCW programs in each State and divide weapons between those that can be owned by anyone (which would have restricted capacities, non-detachable magazines, etc) and those that can only be owned by someone with a valid CCW permit. As a starting point for what constitutes a permit-free weapon, a revolver would pass. A basic bolt-action hunting rifle with a built-in magazine should pass too. Given the popularity of .22LR semi-automatic rifles (.22LR is a relatively weak type of ammunition, so such rifles are extremely popular as user-friendly plinking and target practice guns), it might also make sense to relax the restrictions for guns carrying certain types of ammunition.
It would be up to each state to determine the rules for CCW permits and over time States can experiment with tests of responsible gun ownership, handling things like "Weapons being stolen" on a state by state basis. (I'm not in favor of laws that punish people for merely having their weapons stolen, or otherwise misused by a third party, although I can see a case for doing so where the theft was in part due to carelessness on the part of the owner.)
Recognizing permits in this way would also solve the argument over the "Gun Show Loophole". Whether the loophole really exists or not, it can be taken off the table if you simply require that any gun buyer, in any transaction private or commercial, either passes a background check or shows a valid permit. This eliminates any issues about the rights of private individuals to sell their own property, and prevents gun shows from becoming exclusively gun dealer based.
This shouldn't be controversial. You're using State laws that are aimed at identifying responsible gun owners, and restricting guns that may need more care to those people. Most existing gun owners would probably, in all honesty, be entirely unaffected by this law. You're also providing the States with a means to discourage irresponsible gun ownership without punishing responsible gun owners.
Of course, I expect it to be controversial anyway...