Edit: This material has been promoted to the core game, as of patch 1.1.1.
No idea if these are going to be useful anywhere, but maybe you want your coilgun to shoot magnets. Might be worse than iron, though -- maybe there is another use for it? Railgun rails?
Disclaimer: I'm not sure I fully understood how to compute the total magnetic moment from available data, and I'm just copying the roughness coefficient from magnetic metal glass because I didn't know how to compute it. Otherwise it is here, for general enjoyment.
Edit: Modified total magnetic moment to match wikipedia's saturation magnetization value in game