Bramble:

The blade stamping is caused by using too heavy a hammer to make the stamp. I can eliminate it by using a lighter strike. All my work is by hand so I'm stuck with "feel" for alot of the work.

450 366: You brought up a good point. A very knowledgeable machinist, engineer or metallurgist could help here, but as for rifling, is it possible that cut rifling would result in a relief of stress that would result {in a very thin barrel} in a propensity for "lifting" {I don't know the metallurgical term} of the metal on the outside of the tube? I know in knifemaking that any removal of material on one side of the blade but not the other can result in warping during hardening.

Has anybody ever measured the bore "before and after" of one of these OSR rifles?