I won't get it back till Thursday. It's an E.A. Brown 26" 1:8 twist 260 Remington. The biggest reason I wanted it crio treated is that when you laser engrave it has localized heating and having done a lot of welding in my lifetime, I know that creates stress risers in the metal. It was crio treated before I set it up in the action the first time. 4140 and 4150 chrome molies react differently to machining than 416 stainless steel, in the world of knife making the stainless steels and high carbon steels, 52-100, react well to crio treating as it helps lessen the graphite around the grain boundaries of the microstructures so that they have smooth edges without any gaps between them that is filled by a brittle substance filling them in. In the world of steam turbines we used nitriding on the surface of stainless steels to harden them for around .030, you couldn't touch them with a file till you got through the nitride finish. Then a crio treatment to relieve the stress and you had a hard surface that was wear resistant but an inner core that wasn't brittle and would grow and shrink at an ever rate with the massive changes in temperatures, kind of like what we do when we fire a cartridge in the chamber of our firearms. With nitrated bolts and studs, we used the amount of stretch in their length instead of a torque value in foot pounds to calculate how much it took for them to still be tight after they heated up and you would ideally only use them through so many tightening's before replacement. In the world of firearms knowledge of some of the metallurgy proprieties is also a good thing as most of us already know, and we are learning more all of the time. If we stamp markings in one side of a barrel we have created stress in that side and as has been said many, many, time for every action there is an equal and opposite reaction, most of the time it really doesn't affect the barrel or it's life for the average hunter, but when we are talking about precision rifles or rifles that the operator's life depends on them , in my opinion, relieving the stress is a good option for making everything as well balanced as can be and not allowing the bullets travels be affected unduly by lowering the possibility of having more drag on one side than the other even in a small area such as we create when we stamp or laser engrave an barrel. Just some of my anal retentive thoughts creeping out again. lol oops dry humor!!!!