Or was it just a cloth saturated with the smell of gun oil and ammunition?

The smell of the uniform and the gun oil caused her mind to drift back many years.

I caught a familiar scent of gun oil and leather.

It was the smell of gun oil on cardboard.

'There looks to be traces of gun oil on the senator's fingers,' Johnson said.

He came back up a long moment later with a black cylinder wrapped in paper that gun oil had turned transparent.

The smell of gun oil and perfume was thick on the air.

He took from it a little bottle of gun oil, brushes, and cloth patches.

I think it must have been gun oil.

It is well maintained and smells strongly of gun oil.