RHoovDawg, I do not know which Turk Mauser, the Turk Mauser is the only small shank receiver that has barrels available because of the large ring, I have chambered two M38s in 8/06 and did not do anything to the feed system. MidwayUSA and Browne's have barrels in 308 Winchester and 30/06 with small shanks for the Turk only.
A problem: To act as a retainer for the top hand guard, the Turks counter cut the front receiver ring, this shortened the length of the receiver ring, a friend purchased 60 Turk rifles for $38.00 each, seems he had a stack of take off barrels and no receivers, he threaded the take off barrels to fit the .980X12 threads, if it was not for the shortened receivers, he would not of had reservations about going above the 30/06.
http://www.turkmauser.com/serialNumbers.aspx
F. Guffey