O/W/D; Went back & checked the previous posts & perhaps we didn't exactly cover the difference. Essentionaly the difference between "Plain twist & Damascus twist" is; For plain twist bbls, layers of iron & steel are welded together, rolled out into a flat bar & this bar is then wound around a mandrel after which the edges are welded forming a tube. This gives the candy cane pattern Oscar mentioned in his first post. Damascus is started in a similiar pattern, But, the bar itself is twisted, like it is held by one end & the other end rotated, until it looks something like a threaded rod. This rod is then heated & hammered flat & depending on the grade 2,3 or more are welded together along their edges & then this is wound around the mandrel. Pattern on the damascus is varied by the way the pieces are laid before the first welding as well as the size & no of strips used. This is why the plain twist just has the spiral pattern while the damascus can have any number of patterns & gives what is sometimes referred to as the fingerprint type pattern. One variation of the twist is what was known as stub twist, the originals being made from horse shoe nail stubs & chopped up coach spring steel of about the same size as the stubs. This still has the spiral pattern but appears as small pieces in instead of one continuos strip, but every thing is still just going around the bbl in a spiral. The term wire twist is often used. This comes from the appearence of plain twist. This is hard to explain but if you can imagine the strip used for winding on the mandrel is composed of many pieces laminated together. As this strip is wound the laminations are edge wise so that after winding around the mandrel you are looking at the edges of the laminations with each piece going through to the bore. This gives about the same appearence as if it had been wound with wire, welded & struck smooth, thus the name wire twist. I realize this is not a real good explanation but hope it clears it up a little.
Miller
