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.
Look at the bright side of it. If the ATF comes to confiscate firearms, it will create jobs. Nearby, in Sand Mt. Alabama, would be a good place to teach young ATF recruits how to confiscate guns door to door!
Just bury the pipes why waste $ on the pvc.
When i was in the CG in Miami I used to sit on the beach on my days off and watch the old codgers with their metal detectors.
I took a few packs of BB’s with me one day and got there b4 them and sprinkled them all over the place.
What a hoot the BB’s would fall through the strainers they used and it would drive them nuts.
If it is time to bury them then it is time to use them.