Which Spanish Mauser are you talking about?
There Was a Model 1893, an 1895, a 1943 and 44 (Which are both 1898 Type Mauser action). Then there are Sub models like the Model 1916, which uses the 1895 action, and the FR-7 which also uses the 1895 action and then the FR-8 which uses the 1943 Spanish action.
You see why I ask "which Spanish Mauser"?
Out of all of these, the only ones that would do what you want, would be the 1943/44 (The 1944 is just the Spanish Air Force version of the 1943) and of course the FR-8 which is essentially the same action.
You probably don't want to build a .30-06 on any of the others as the are not suitable for the pressures of the cartridge.
I hope this helps. Merry Christmas.