I inherited a “sporterized 8mm Mauser”. Looks like original military barrel. I also inherited a large number of rounds that are factory ammo from the Olin Winchester factory in East Alton, IL. These have 170 grain bullet. 2500 FPS on the chronograph. Not sure on powder. When I shoot them at 50 yards they group pretty well, but from 50 to 100 yards they sail high about 12”. Because I have all this ammo I picked up an M48 and the bullets do the same thing in this gun. Is there something about the Mauser rifling and these 170 grain bullets that causes them to sail high? Not sure if I should just shoot them all and reload to a bullet that these guns like, or just knock them apart, save the powder and reload to a different bullet. Any thoughts are appreciated.