Airguns as preps

Since air rifles are just about completely unrestricted by the government advances are being made in the technology.
About the only restrictions on air rifles is your "air rifles silencer" can't be removable unless you want to pay the $200 tax and mess with an NFA silencer. But otherwise if you want a full auto built in silencer air rifle that spits out bullets like a 22LR? No problem as long as you are 16 years or older and have some money.
You can get a 30 or 35 cal full auto air rifle that would be pretty close in muzzel energy to a 32ACP carbine.
Here is the "aliens pulse rifle of air guns"
Delta Wolf - Daystate not full auto, I don't think, as far as I can tell but you can adjust the velocity via built in computer with chronograph and it has a shot counter.
If you are a wasteful capitalist pig and must have full auto here's some of those.
5 Best Full-Auto Air guns
There's 2 classes, full auto bb guns which are just dangerous toys and full auto air rifles that fire lead bullets up to 35 cal, these are viable weapons.
They cost up to a few thousand dollars but that's a lot cheaper than the cheapest full auto 22lr and there's no ammo shortage for air rifles, since all you need is the pellets and compressed air.
You get what you pay for. The $2,000 ones are fullauto and appear to be more accurate than a bolt action 22lr on semiauto mode.
My gemtech mist 10/22 is about as quiet as a pellet gun, it's semiauto only. About $2000 in that.