A new homeowner found an unwanted “cache” in his attic.
A man who had recently moved to Skelmanthorpe found a handful of bullets in his loft.
The householder was rooting around in the roof space when he came across seven large bullets.
Pc Sally Baines, from the Kirklees Rural Neighbourhood Policing Team, said: “He was planning to sort out the loft insulation this weekend, so went up to have a look round and make sure everything was sound.
“He found a metal rollerdex in the corner of the loft, and inside found the bullets and some other items.
“We’re not sure if the bullets are live at the moment but firearms will be checking them out.”
The resident rang 101 on finding the ammunition and two Special Constables were dispatched to the address, SC Dale Wilson – also an award winning bingo caller at Huddersfield Mecca – and SC James Hemsley.
It is thought the ammo could be World War Two era.
It was taken away to be analysed by the police and will probably be melted down.