After a ton of research and searching I have found a Factory load that will be fine to shoot in your Gew 88,s and 91,s.
I was told you have to reload to safely shoot these older guns but this stuff works beautiful.
Remington Express Core-Lokt 8mm MAUSER 170 GR SP R8MSR.
It is a low power sporting cartridge with a bullet diameter of .318
It is hard to find and pricey. about 35-40 for a box of 20rds. reloadable
I was told you have to reload to safely shoot these older guns but this stuff works beautiful.
Remington Express Core-Lokt 8mm MAUSER 170 GR SP R8MSR.
It is a low power sporting cartridge with a bullet diameter of .318
It is hard to find and pricey. about 35-40 for a box of 20rds. reloadable