Antonio Callaway had gun parts and ammunition in his car (in addition to weed) when he was pulled over in Ohio ... and the police video obtained by TMZ Sports shows it made the lead officer get "real nervous."
The Cleveland Browns rookie WR -- selected in the 4th round of the 2018 NFL Draft -- was pulled over on August 5 at 2:59 AM in Strongsville, Ohio for a routine traffic violation.
The cop smelled weed and searched the car -- finding a small amount of marijuana under the driver's seat .