Lonnie Vernon had pleaded guilty in U.S. District Court in Anchorage to buying a gun, silencer and hand grenades, and having maps to a federal judge's home in August 2012, KTUU-TV, Anchorage, reported Tuesday.
The conspiracy for which Vernon was sentenced developed over paying taxes, officials said.
Karen Vernon, his wife, was also scheduled to be sentenced for her part in the scheme.
The couple were members of the Alaska Peacemakers Militia. The leader of the group, Schaeffer Cox, has been convicted of conspiracy to murder federal officials and owning illegal weapons. He is scheduled to be sentenced Tuesday.