It used to be that paper currency was backed by gold and silver for its value. A 10$ paper note would be redeemable for 10$ worth of gold or silver following the gold or silver standard. Currently our bills are fiat money which means they are not backed by any tangible item. They’re just based on the strength of the economy. The economy can fluctuate so it makes the actual value of a bill unstable. These Mcdonalds coins, however, would be a currency that are redeemable for a Big Mac. This would make them a technically more stable currency as they are always have the value of a Big Mac they can be redeemed for.
The United States Undetectable Firearms Act of 1988 (18 U.S.C. § 922(p)) makes it illegal to manufacture, import, sell, ship, deliver, possess, transfer, or receive any firearm that is not as detectable by walk-through metal detection as a security exemplar containing 3.7 oz (105 g) of steel, or any firearm with major components that do not generate an accurate image before standard airport imaging technology.
This is on the defcad website. All of the schematics follow this law.
The virgin NRA member vs the Chad defense distributed member