Authorities accused the 30-year-old Marine of having a live 25mm explosive round in his checked bag at the Palm Springs International Airport.
A man is in custody after explosives, guns, and narcotics were found inside his home in Lemoore.
The device hidden in the bag's lining was a circular compound, about 3 inches in diameter, that had two fuses and powder concealed in wax paper and plastic wrap, according to the criminal complaint.
Investigators say an off-duty officer saw the driver of the Tahoe toss fireworks and a pipe bomb out of the vehicle.
The Sanger Police Department posted an x-ray photo of the artillery round on social media.