A grenade launcher has been handed in to West Midlands Police.
The weapon may be sent to a museum
The shoulder-held, rocket-propelled weapon was left at Brierley Hill police station on Saturday.
The grenade launcher's former owner took advantage of a nationwide amnesty that allows people to hand in weapons without fear of prosecution.
A West Midlands Police spokeswoman told BBC News Online it is pleasing that the weapon is no longer a threat to the public.
"We're quite surprised, but it's another weapon off the streets and it shows people are taking the amnesty seriously.
She said the force is still deciding what to do with the grenade launcher.
"We might keep it as an example in our armoury or it may go to a museum."
The spokeswoman added that the police do not know anything about the person who handed the weapon in.