doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Forging lines on old actions?

I'm with gunman...in my experience some of those lines can go quite deep and you would never be able to file them away.

I'm not an metallurgist, but I believe we have a member or two that is. Possibly Dick Dup. He can probably give a technical explanation of the possible causes of these lines.

I know there are many different defects that can occur in forgings.

Those look too fine to be cold laps, but hard to be positive from a pic.

I think many folks have seen wrought iron inclusions (silicates?), but there's usually a 'grain' to it. I see lines that cross near ninety degrees to each other, might be hard to do that by forging metal without some distortion.

I'd still guess, in that particular picture, maybe those are rough filing marks that telegraphed through the finish because they weren't seen or the part was taken to some final dimension.

I believe it is a typical by-product of the steel manufacturing technique for small batches production in the late 1800's. Prior to widespread adoption of Bessemer's Converter and crucible steels a different technique was used. It was known as fa-g-g-oting (strange but true) Iron rods were drawn from pure puddled iron. @ 1/2" diameter. The rods were then case hardened by cementation method for @ 24 hrs to infuse carbon into the iron.After case hardening they where cleaned off, fluxed and bound together into a bundle(fa--ot) of 10-20 rods. then heated to white heat and pounded together. The end result was a billet of steel. Incidentally the Birmingham gun quarter was/is bordered by Steelhouse Lane which reflects a business that performed this method.The marks one sees are the boundaries between rods. As a production technique it disappeared around the year 1900.

Thank you for your explanation Hugh. After seeing many examples of this over many years, yours is the first detailed description of what was the cause that I have read. Terry

Are they an indication of weakening structure as has been suggested to me by one of my gunmaker friends?

Blue Grouse, You'll find a good answer to your question in a little known, but very interesting book: Fighting Iron, by Art Cogan.
Sorry, I don't have it on hands now, so I can't tell the exact page.

Check old Highwalls. Most all of them have forging lines.

If what Hugh Lomas says is true, and it does sound very plausible, wouldn't it be fairly easy to confirm by draw filing and then rust bluing one of these actions by the same process used to blue or brown Damascus barrels? Since the case hardening infusion of carbon into the pure iron rods would only be a few thousandths thick, subsequent hammer welding and forging of the fagg*t would not give a homogenous steel product, but something more akin to an action forged of layers of iron and steel, i.e. Damascus. Rust bluing followed by etching would leave the high carbon areas blue/black while the pure iron areas would be etched white.