Jim
Tensil strength of common stainless is in excess of 50,000 lbs and the steel used in common grades of "soft" barrels are around 20,000. When I say common soft barrels I mean Browning supers, Parkers, Flues,ect. Some of the newest barrels may stand up to a stainless brush. It appears that you are the kind of guy that needs to use tornado brushes on his best so the value increases with the ease of cleaning. Ryerson service centers used to publish the you are requesting.