If it gets to that point a few PVC Tubes filled with some desicant capped and burried out back some place is a plan.
The `run’ over the next few years will be on burial gun vaults if Bam gets frisky, and I think he will.
I read about a guy in England years ago who decided to destroy his AK47 rather than turn it in, so he rammed it barrel down into the earth then ran some sort of wire contraption to the trigger.
It kept blowing itself out, undamaged. So he finally cut it up with a hacksaw. But that’s the English for you, and look at them now.
I’ve heard white rice is a good dessicant. Also, you could, hypothetically, drop in dry ice, let it melt and displace the oxygen in the vault, and then seal it.
If the ATF actually starts looking, it might be fund to bury a couple dozen PVC tubes in the yard - each with a 4" to 2' iron pipe. In that situation, any backup firearms should go someplace safer - some ready to use and others where they will not be found, not even with metal detectors, but also where they will not be lost or forgotten.
It it’s time to bury them, then it’s time to use them.
If you feel that it’s time to bury them it’s also the time to have them in your hand.
Cleaned once a week, loaded and racked next to the door that anyone would come to first. That is where a firearm belongs.