I have to hit the metal hard enough to deformthe band.
Well, Wendy, it’s a little secret… I have a friend who has
calculated rings so that he can make a strip, hammer it and it will
stretch to just the right size. Now, if the band is already made then
you have two problems, really - even three… One is that it’s darn
difficult to hammer with force hanging on a ring mandrel, the second
is the deformation, as you say. And the third is that you’re going to
change the ring size by up to a couple of sizes, depending. So don’t
hammer it… … Get a giant round/ball bur and go over
the whole ring, being careful to keep it random. Then go back with a
rubber wheel, leaving more or less texture behind as you like.