Let me fill you in on the Model 38 Turk Mauser you have.
You have a large ring Mauser model 98 action that has small threads.It is kind of like a hybrid 98/96.
The bolt and receiver are like a 98 and the barrel threads like a 95 or 96 being smaller in diameter than a 98.
I have built sporters on thes actions:
Here is a 25-06:
Here is a .308:
(the 280 is a VZ24):
Keep in mind that if you build on a '06 based cartridge that you must alter the magazine well to accept the longer cartridge or seat the bullet a little deeper than usual to clear the mag well.
Good luck and enjoy it, they relly are a good deal these days...
PM me if you wish to discuss selling it.