^

I now use 9.3 Bertram brass though I started out 25 yrs ago with 8mm Mauser and the expansion ball shortened the neck length greatly.

Remember old MS rifling was quite pronounced so measurement is recommended.

44 to 45 gns MAX of 2206 (3031 equiv) with 270gn RN Woodleigh (Hornady for range work). Your mileage may vary so start at 42gns and tread carefully. I started at 42 gns for only 1850fps.

Check the COAL against the chamber by loading dummy rounds.

RN only though most blunt nose 235 grainers can work. Recoil with 300 grainers may split what is a very thin stock so I'd recommend 270 gn pills max.

Opinion only so once again, safety first.