A ball screw is a pointed, screw like, metal device attached to a ramrod used for removing lead projectiles and/or patches from muzzleloaders.

A ball screw can be used with or without a collar.

Footnotes / Sources:

“Glossary ⇒.” Sporting Arms and Ammunition Manufacturers’ Institute. Ed. SAAMI’s Technical Committee. Web. 15-18 Jan. 2011.