Boolean creates a hollow object I am trying to carve out some wear lines on a bullet, from where the barrel of a gun would cut into the metal. I am using a boolean modifier on the bullet, set to difference.

It cuts into the object ok, with the striations / wear lines in the right place, but the bullet is now hollow inside. Is there a better method to achieve something like this?






EDIT: Hollow effect appears when boolean object is close to flat end of bullet.
Ok, it turned out to be an issue with the original object being non-manifold on the example I posted.

When I replaced it with a simple torus (which was manifold) the error occurred again because there was accidentally an edge split modifier as well. When I moved boolean above the edge split, in the modifier panel, the hollow look disappeared.