The 150 gr bullets would have been designed for the 8x57mm and much lower velocities. They will be fragile at 8x68S or 8mm Rem Mag velocities.

I haven't handloaded for one but have shot a mates 8x68S. I would choose a bullet like a 200 gr Nosler Partition or Barnes X in a similar weight.

It depends on what you want to shoot. ???

I would give a 185 gr Core-lokt a try on pigs and medium sized deer but prefer Nosler or Barnes X. The 150 grainers would work well enough on varmints.