I had a .303Rigby that shot about 1 foot high at 100 meter, with 174grain bullets doing 2300 ft/sec.
when I loaded the traditional 215grain it came down. Actually on my first load session they printed dead-on. Velocity was just barely 2100 ft/sec. The original .303 in black powder did about 1900 ft/sec, where the smokeless version improved another 200 ft/sec only.
With that kind of ballistics, would hardly today be considered adequate for any serious hunting but rather just an amusement for re-enactors and gunbuffs..