RE: Arrow weight vs Arrow speed
Ask yourself this, Is it easier to stop a sports car going 75mph or a bus going 55mph. A heavier arrow once in motion is harder to stop then a lighter arrow plain and simple meaning better penetration. Heavier arrows also maintain downrange speed at a higher rate then the lighter arrows meaning highe KE downrange then specs show on the chrono shot at 10yds or less. That is why recurve shooters typically shoot heavier arrows that are not shooting higher speeds yet are able to get passthroughs on large animals.