Hello and good morning. This is a quite new barrel and I was trueing up the muzzle end and found that there was a bright layer of metal about 2 mm. thick on the outside, steel coloured. Also the same round the bore,the 'metal' in between was grey and very course grained, not as hard as the steel , before anyone asks it was not sand but looked like course sand, the lathe tool cut as if it wasnt there but it did not crumble.
I suspose it might be normal but in my limited exspearance I havn't seen anything like it before.
What do you think chaps, is it me asking a silly question, again!
Thanks and all the best.
Geoff.
PS. rifled and non choked bore.