Anonymous Background Check

First off, for the existing supply of legal guns outside an FFL, any universal background check is going to be on the honor system.

The supply of illegal guns isn't, ever, going through any background check system regardless of how illegal you make it.

There are legitimate fears that universal background checks are de facto registration and will lead to confiscation down the road.

The fear is legitimate because confiscation has already happened in states with registration.

A 4473, which I am told isn't registration, will have an amazing ability to allow law enforcement to come to your door asking about a particular gun.

If they ban any particular model then they will "just" have to comb through an FFL's 4473's and then swing past the address listed.  Probably cross-reference it with change of address forms.

At present, you can have sold the gun and not record where it's gone.

With universal background, you will have to tell them where the check was done and that will lead to the next owner.

But once there's a ban, betcha money that a 4473 with your name on it and a banned model will become grounds for a warrant and all of your still legal guns are going to be recorded too.

Politicians are simplistic creatures.

But I have something of a solution, if we must have universal background checks.

"Anonymous" checks.  It's simple enough to create a database of the criminals.  You hit the web page, enter the buyer's information and get a go/no-go from the database and a confirmation number.

That number proves you did the check, should something trace back to you and you no longer have it, but doesn't record what was sold.

If both parties are legal to own it, there's no need to record it.

This is only if we must have universal background checks.

And it will still be on the honor system, like a de facto registration system is.

Still, any system is only as good as the data input into it.  I seem to recall a mass shooting where, although the shooter was a prohibited person, the Air Force had neglected to file the proper paperwork...