Sorry, Savage is the only one who would know for sure what the A.I.S.I. number of the steel (what grade) they use in their barrels is, and, what the properties are after heat treatment. Anything else would just be second hand info or a guess. Manufactures don't usually give out such info, instead they may give a 'specification' number. It is an engineering 'specification'. That 'specification' is a set of given properties that the finished product is to have upon completion (hardness, tensile strength, shear strength, durability for a given purpose, machinabilty, ect.,ect.). There are, sometimes, many different grades of steel that will meet that 'specification' with a change in heat treatment. I worked for a bearing manufacturer for quit a few years, the material we made the 'inner' & 'outer' out of, and their heat treatment were considered 'propriety information' to be kept within the company. I can see why companies don't just give out info like that. It is engineering and R&D that they had to pay for, why give it away?
