How can I finish the barrel on my Kibler kit?
For iron or steel parts including the barrel, we recommend JAX Black. It gives an aged black patina, is simple to apply, does not require heat, and avoids the warping risk that comes with bluing. Other options include leaving the barrel in the white to age naturally, browning (a late-1790s and later finish, well suited to post-Colonial styles), or a polished-bright finish. Bluing is generally not recommended because uneven heat can cause the barrel to warp; if bluing is desired for historical reasons, charcoal bluing is the only period-plausible option for Colonial-era work and still carries warping risk unless done carefully.