I believe the Gewehr 98s of the the WWI era were sighted for the 196gr spitzer boattailed ammo of that era. This ammo was intended primarily for longrange, mass machinegun fire, a tactic of that war, but was also used in the infantry rifles to simplify logistical demands. The 150gr ammo was available in the years before WWI, when the Germans switched from the 227gr .318" roundnose to the "Spitzgeschoss" or 150gr .323" bullet. They switched back to the 150gr bullet just prior to WWII.