One disadvantage I think to case hardening on centerfire rifles is that if the case is very thin, the constant pounding can drive the hard case back into the softer core.
For example, the bolt locking lugs and the recesses in the receiver. That can cause the recesses to indent, causing excesive headspace and difficulty in opening the bolt. The inside is spongy, and gives very little support to the thin outer case.
Much would depend on the quality of the case hardening, and also the quality and hardness of the metal under the case. That would also apply to through and through hardening as well.
Several years ago, I purchesed a 98 Mauser action through mail order (you could do that at the time). When I got it, the crest on the front receiver ring had been ground off. It had something to do with an obscure rule or law that some countries could not sell their surplus actions if they had identifying marks on them, or the U.S. could not import them.
I sent the action to Douglas to have a barrel installed. The action was returned, with a note saying the action tested 0 on the Rc scale, and they would not put a barrel on it.
When the crest was ground off, the outer case was also ground off, leaving only the soft core.
