Yeah, that could work, but crims get their guns illegally as do they for ammo.
We need to shut down the avenues by which criminals are getting illegal guns.
That's a no-brainer isn't it?
Come down HARD on illegal gun transfers.
ALL gun purchases for that matter.
Start getting them off the street in greater numbers and start making sure manufacturers are held accountable for each and every one in addition to every single owner in a detailed chain of custody database.
Sure, it will take a long time....but within a couple generations the government could easily have a detailed record of every firearm in America....where it is located and who it is assigned to.
I can hear the screaming now....
"THAT'S CRAZY! I DON'T WANT NO DAMNED GUV-MINT KNOWING HOW MANY GUNS I HAVE!"
To that I say get over yourself.
You are NOT as important as you imagine yourself to be.
As long as you are not misusing your firearms the government has got more to do than pick on you and raid your double-wide to confiscate your squirrel gun.
Now let's talk about ammo.
It should be HARD to get.
F-ing hard!
Same with reloading supplies.
Stringent registration procedures, insurance, tracking in a national database, etc.
If you are already sitting on a sizeable cache for the day some idiot like Donald Trump commands you to march on Washington and "take back yer guv-ment" then good on ya!
As long as you're not actually using it it can sit there till hell freezed over.
It is (temporarily) harmless.
The moment you load it up and attempt another coup (treason) againstthe U.S. Government though then you need to be disarmed....IF you survive.
Which you probably won't.
Either way, problem solved.
But IF you are a criminal or a "gangster" who is out there burning up their ammo....then good.
Every shot you waste is one less round you will ever have.
Because you won't be able to buy more.
There is no more black market for it and legit ammo dealers won't sell you any because according to the database you don't even legally own a weapon that requires the tound you are attempting to purchase.
So you are arrested on the spot.
Again, problem solved.