Your initial question was about a Ruger 77. The Ruger's angled front screw would be an issue.
In the 50's,60s,and 70's cheap Mausers were in barrels in every hardware store,Bishop and Fajen offered stocks and Everytown had a gunsmith that would convert them to sporters.
Rifles seldom go to the dump.
There is another variant. A "utility rifle" .It was not about the fine gunsmith's art.The original stock forend was shortened,handguard removed.Maybe a receiver sight was fitted.
But pretty much,the barreled action is intact. That would be your prize,maybe.
If you really want a modern sporter,the 98 mauser action was used in JC Higgins/Ted Williams sort of rifles,Brownings,Mark 10's,and many others.
Any of those will go into a military stock with minimal work.Beware there are some variants,such as the Yugo,that have a different length.and guard screw spacing.
Quality stepped,military contour pre-threaded and short chambered barrels are available from Walther.
To simply rebarrel a milsurp mauser to 308 does not always feed properly.
The 308 has less case taper.Its fatter at the shoulder. Which means the mag stack gets tight at the shoulder dia while it is still loose at the case head.
The bolt will tend to over ride the case head,then bite into and crush the side of the case.The round feeds about half way up the ramp before everything jams up.
Of course,it can be corrected. There are plenty of .308 Mausers.
But just screwing in a barrel might leave problems to solve.