This might help Richard
Greener on Stub Twist in
The Gun, or a Treatise on the Various Descriptions of Small Fire-Arms , 1835
http://books.google.com/books?id=oIEY4qL6_z0C
Stub-Twist Iron - Made from a 1:1 ratio of horse-nail stubs (iron) mixed with chopped coach spring steel, fused ("puddled") into a "bloom of iron", then hammer forged or rolled into a rod NOT twisted, which was then wrapped around a mandrel and hammer welded.
Appleton's Dictionary of Machines, Mechanics, Engine-work, and Engineering
D. Appleton and Company 1873
http://books.google.com/books?id=zi5VAAAAMAAJ
Gun Barrels
http://books.google.com/books?id=zi5...AJ&pg=PA936&dq
It need hardly be remarked, that the advantage to be derived from the use of horse-shoe nails does not arise from any virtue in the horse's hoof, as some have imagined, but simply because good iron is, or ought to be, originally employed for the purpose, otherwise the nails will not drive into the hoof; and the iron, being worked much more, is freed from its impurities, which can only be effected by repeated workings.
For the finest description of barrels, a certain proportion of scrap steel, such as broken coach-springs, is cut into pieces and mixed with the iron by the operation called puddling, by which the steel loses a considerable portion of its carbon, and is converted into mild steel, uniting readily with the iron, and greatly increasing the variegation and beauty of the twist.
Several authors commented that horse-shoe stubs became increasingly difficult to obtain by the mid-1800s leading to more Plain Twist/Wire Twist/ Skelp (all the same stuff) and Laminated Steel barrels
More information here
http://docs.google.com/a/damascuskno...LxMESM3W0/edit