Read and understand the history of the laws on firearms.
http://www.pennlago.com/are-firearms-without-serial-numbers-illegal/
When a serial number can
HAVE been obliterated depends on many things.
Hints:
1. Suppose there is a non-NFA firearm which was manufactured PRE October 22, 1968. The firearm has no serial number. However, the firearm never had a serial number.
The lack of a serial number does not render the firearm illegal.
2. Suppose there is a firearm which was manufactured POST October 22, 1968. If the firearm has no serial number, and never had a serial number,
the lack of a serial number renders the firearm illegal. [Except a non-NFA home manufacture that you have no intent to sell, which we will explain later.]
3. Suppose there is a firearm which was manufactured POST October 22, 1968. The firearm had a serial number, but it has been removed.
Possession of this firearm is illegal.
4. Suppose there is a firearm which was manufactured PRE October 22, 1968. The firearm did have a serial number, as the manufacturer had utilized serial numbers on its firearms voluntarily. However, the serial number was removed for aesthetic or other reasons AFTER October 22, 1968.
Possession of the firearm is illegal.
5. Suppose there is a non-NFA firearm which was manufactured PRE October 22, 1968. The firearm did have a serial number, as the manufacturer had utilized serial numbers on its firearms voluntarily. This serial number was removed BEFORE October 22, 1968.
Under the GCA, possession of the firearm is illegal. However, this is the most difficult scenario we will discuss, and here’s why:
....
Read the whole thing. It is interesting and complex.
You 'might' be changed (and have to defend in court) if you have a firearm with a obliterated serial number that was legal before the GCA of 68.
Depends on who is running the ATF and what their slavemasters tell them to do.
Do you want to be a test case?
Deaf