Normally the common 8mm bullets are too soft for the 8x68S or the 8mm remmag but Nosler partition, RUAG CDP or this here!:

http://home.snafu.de/l.moeller/8x68S.html

are not too soft for the magnums!

Even with the new light 8mmS bullet (9gramms) the velocity is just about 1100 m/sec!!! And the penetration ist still very high!