I just had a look at the bottom of the action of a Holloway SLE Pigeon (not a best work gun, but no slouch either) of 1890ish vintage. I has these "stripes" clearly visible and easily mistaken for scratches. The look I took included a 2X to 12X folding pocket glass made it clear that they are not scratches of cracks. A 30X pocket microscope was ver interesting. Along the "stripes I found several areas of both black and white inclusion; very narrow/thin bands of inclusion, but definitely inclusion of something not steel, things that would qualify for Chuck's dirty steel.

I'll look at a few more guns and see if I get similar findings. Photos --- mmmm, I dunnno, we will see. Most interesting!!

DDA