I have access to a machine shop and doing mill work would not be an issue. So...dont try this at home kids.

Would cutting a recess in the barrel similar to the Savage 340 E, and also adjusting the shoulder of the chamber to compensate for the recess, work ?
or
would it be better to re-purpose an existing 340 30-30 barrel to mate with the 110 action. Also getting a donor 30-30 (as if there is such a thing) bolt head and mate that the the 110 action.

Both methods would provide the additional support that Blue is looking for. Also looking at the attached gif, would this same rear case expansion still exist and does currently exist with all 30-30s currently ?

Yea, this may turn into a $5000 lump of junk. But its an interesting project.