A gun serial number is a unique identifier assigned to a singular firearm. In the US, federal law requires registered gun dealers to maintain records of gun serial numbers and then to report them when they are sold but federal law also prohibits creation of a national register.

Is it illegal to remove serial numbers from guns?

The Gun Control Act of 1968 at Title 18 United States Code (U.S.C.) Under 18 U.S.C. 922(k) and 26 U.S.C. 5861(g), it is unlawful for any person to possess or receive any firearm which has had the serial number removed, obliterated, or altered.

Why do people remove gun serial numbers?

Because most firearms on the street are stolen - The serial number links the gun to the crime committed to obtain it. If that crime includes a shooting or a murder, then the holder of the gun may find themselves linked to that crime, whether they are guilty of it or not.

What is the biggest problem in making an identification in bullets?

One of the biggest problems in making an identification is that few evidence bullets are submitted intact. Most are badly distorted, wiped and/or fragmented.