A Rastrick man will appear at Calderdale Magistrates Court after police found a haul of weapons at an Elland factory.
The 19-year-old has been charged with firearms offences after an army bomb disposal team was called on Wednesday.
A second, a 69-year-old man, has been released on police bail pending further inquiries.
The drama unfolded after police were called to reports of an industrial accident at the industrial unit on Halifax Road at 12.35pm.
Two decommissioned grenades, three licensed shotguns and a further firearm were found at the site.
The industrial unit was taped off and officers on duty are still guarding the scene.
Anyone with any information should contact Calderdale CID on 101.