Yep. For a couple bucks and with basic hand tools one can make a single shot gun of any caliber. Pistol and Shotgun are extremely easy and safe.
Bingo. Elastic bands can also be useful
Amen BroAnon, fortunately most weapons in the US are not even traceable…a fact the powers that be would not have you know. There are a shit-ton of legacy firearms in the country and they will never be able to figure out where they are and who has them let alone get a true number of how many there are.