150-155gr MatchKing, Rem .308 Brass, CCI-200 primer, 44.0gr-46.0gr Varget, 2.810" OAL.
168-175gr MatchKing, reduce load by 1.0gr to 2.0gr. These are all full power loads, and I wouldn't load any hotter.
The Ishy is built to handle NATO ball ammo loads, and does not need to be downloaded like the Krag. It is, however, a lightweight rifle and can develop a lot of recoil with heavier bullets. Prone with 175's can get to be something of a punishment.
I specify Rem Brass because that's where my experience comes from. Lapua should perform similarly, but may be unnecessarily expensive for the Ishy.
I no longer own my Ishy (or any .308), but I really enjoyed mine when I had it. Best of luck with yours.
Greg