Most bow hunting (AFAIK - as bow-hunting is illegal in the UK so I'm going on published info) is done using a compound bow. This uses cams to store the load and means that the archer can hold the bow at full draw for long periods with relative ease (out of a 60lb draw weight perhaps 15lb is on the fingers) combined with a magnifying/self-levelling sight and a string peep this would enable a competent archer to group very tightly say, a dozen in a 2 inch circle. A mechanical release can also be used to smooth out variation in loosing. Because they make very little noise on release, bows do not startle the game and ensure cleaner kills. Arrows do not break up on penetration and bounce around inside the corpse like a bullet will.
For their highly precise accuracy compound shooters may not compete with olympic and longbow archers and two compound archers of my acqaintance both regularly score close to maximums.
Tough luck Phot, my worst Portsmouth this season was 460, though I'm averaging 490.