A two-week amnesty on illegally-held guns and ammunition has begun in Staffordshire.
The surrender, in response to a law change in July, will allow owners of antique or unwanted firearms to hand them over without fear of prosecution.
Police said they feared such obsolete weapons could be "made viable by criminals with ballistics know-how".
A similar West Midlands Police scheme saw a 1940s rabbit-hunting gun - stored in a loft for decades - handed in.
The Staffordshire force said it hoped people holding guns "in innocence and ignorance of their illegality" would take the opportunity to surrender them.
In July, the maximum penalty for possession of an illegal firearm increased from 10 years' imprisonment to life.
Supt Mick Boyle encouraged people to check attics, sheds and cupboards for forgotten weapons.