The Riverside Press-Enterprise reports ( http://bit.ly/1faHVtB) the 9th Circuit Court of Appeals ruled last month that Joel Cleve Miller should have been allowed to present testimony from two witnesses, including his ex-wife, to back his claim that he was framed.
The U.S. Attorney's Office hasn't said whether it will seek a retrial.
The 42-year-old Miller served nine months of his two-year sentence for the 2010 conviction.
Prosecutors said the AK-47 came from one of Hussein's palaces. The Hemet resident served in Iraq for 14 months.
Miller's attorney didn't return requests for comment on Monday.
Information from: The Press-Enterprise, http://www.pe.com