Only in Amerika!
Under U.S. federal law owning a ghost gun is allowed, assuming that no other impediments exist. ...
The FBI does not generally track the use of homemade firearms. ATF agents say that ghost guns are
sold at a $1,000 premium due to being untraceable.
Is it legal to own a gun without serial number?
Federal law does not prohibit an individual from making a fully functional firearm for his or her own use. Further, you do not need a federal firearms license (FFL) to manufacture the gun. Refer to 18 U.S.C. 922 (firearms crimes) and 18 U.S.C. 923 (firearms licensing) in public law.