Neat! but barrels and actions are low strength steels in the scheme of steels. They are not hardened much and that's why they don't crack when someone engraves the breach with a sharp cornered tool or cuts a dovetail to splice chambers together like a M21. This article is talking about high alloy steels of extreme tensile strength, probably above 200,000 psi tensile strength. For perspective, our early 20th century gun frames are probably around 70,000 psi or so and the barrels might be near 100,000 psi on the really good stuff.
