Don: from the 'staining' thread

Steve said "1002 steel may be close to what was used in barrels."

and I agree

The chemical composition of only TWO samples of pre-1900 2 Iron Crolle was similar to AISI 1005 low carbon, low alloy steel based on Optical Emission Spectroscopy (OES).

Wrought Iron may have .05% - .25% carbon, so the steel component had to be very low carbon steel.