are steel. Some of them are plain cast iron, while the best and strongest of the Marlin Ballards are forged of Norway Iron, which is a high-grade wrought iron: it is NOT steel, but was case hardened and sufficiently strong for the original black powder pressures they were made for. The Ballard action, admirable as it is and well liked for building accurate rifles, is still a relatively weak action, not at all suited to the pressures of modern cartridges or smokeless loads which produce higher maximum pressures than the original BP loads - and that lack of great strength is due to the mechanical design of the action, as well as the materials of which it is made.
PRD1 - mhb - Mike