Back in the 70's, I bought a 98 Mauser Gewehr(I think). in .30/06.
Indeed, it had the military stepped barrel, but a .308 groove diameter barrel & chambered '06.
I gave that rifle to my bro and he used it on the Queen Charlotte Islands(now Haida Gwaii) with 150gr.
Dominion/Imperial ammo for deer & it shot very well. The barrel looked brand new inside. Don't know who built it,
but it had the laminated mil. spec stock as well as military sights.
Strange "pieces" of history.