ORS 166.450: Obliteration or change of identification number on firearms.

Any person who intentionally alters, removes or obliterates the identification number of any firearm for an unlawful purpose, shall be punished upon conviction by imprisonment in the custody of the Department of Corrections for not more than five years. Possession of any such firearm is presumptive evidence that the possessor has altered, removed or obliterated the identification number.