If someone is looking for real-world expertise on comparable real-world weapons (i.e. the famous English Longbow),
this book from Osprey Publishing is very informative. In general, Osprey publishes good treatments of military aspects and their books on ancient and medieval topics are very useful as research sources for games as well.
On the specific topic, the author (who makes heavy use of expertise from the British Longbow Society; see
here for some information) shows some interesting insights.
For practice shooting on stationary targets (approximately man-sized), distances between 130 to 345 yards are documented (p. 28). Archers at their peak (early adulthood) were (with war and not practice arrows) "required to be able to shoot with accuracy at a range of 220 yd." (p. 33). This matches well with the practice ranges mentioned earlier.
He argues that even though distance shooting in battle was possible, it was possibly not the focus, as it would mean to spend a lot of ammunition in an unfavourable situation, where wounding the enemy was much less likely. At ranges beyond 80yd., the penetration power of the arrows decreases in such a way, that it becomes much less likely to penetrate contemporary heavy armour (p. 50). Lightly armoured or completely unarmoured targets are another matter of course, but that book focuses on battles from the Hunded Years War, where heavy armour (heavier and more advanced than in Middle-earth) was widely used. Up to approximately 50 yd. the arrow retains about the velocity with which it is loosed from the bow (p. 50) and thus its penetrative power. Due to these facts (and contemporary sources), the author concludes that in the 14th and 15th century, the decisive "killing range" in pitched battles such as Crécy or Agincourt was at about 50yd. or closer. When we take into account that the Longbow was best in a prepared position with stakes, caltrops etc. to protect him from cavalry charges, the author deduces that the archers would even lose their arrows on such hindered enemies from point blank ranges of 10 or even 5yd. (p. 48/49). At this distance, any hit would be crippling at best and often already killing - even against heavy armour.
In summary, we might note that the "long range" as specified in the OP was in history probably the upper limit of the extremely destructive "death zone" in a pitched battle against heavily armoured enemies.
In a situation where the target was not expected to move (or at least predictably) and/or was lightly armoured at best, effective (including deadly) shots at much longer ranges are to be expected from skilled archers.
Cheers
Tolwen
