Not sure if it was the official or unofficial patch that changed this, but ever since some version of the game, expert bow no longer makes the archer shoot two arrows at once. Instead, it makes each of his arrows deal damage instantly twice, essentially meaning double damage. Same result, half the ammo usage.
Also, as I mentioned above, a well managed Long Hurtful Bow is a
beast.
I think the problem isn't just bows being too weak but also melee as a mechanic being overpowered. For example, in the hands of an expert/master magickal bows and swords from the same tier (charmed, magick, mystic or arcane) deal about the same average damage per action point,
before the strength-derived bonus melee damage is applied, and that one becomes truly insane when it doubles at and above 20 strength.
Now, while it's true that the more powerful bows are decent, acquiring them is truly a pain. A tech archer at least can get a compound bow on his first visit to the blacksmith in Tarant. A magick archer either gets really lucky and finds a magickal/mystic/arcane bow in a chest or - more likely - is stuck with a pathetic short bow followed by an underwhelming elven hunter's bow up to the point when he can get Ellumyn's bow halfway through the game.
If I were to balance melee vs ranged mechanics, for starters I'd make the strength-derived bonus melee damage no longer double at and above 20 strength. Instead, I'd make the stat bonus for 20 strength double a character's carry weight. Perhaps throw in a small perception-derived ranged weapon damage bonus, too.
EDIT:
Dark Elf once wrote:
If anyone ever feels like rebalancing Arcanum, giving guns and bows more stopping power while significantly decreasing their combat speed would be a top priority.
This is also a cool idea. You'd think being shot at with arrows and bullets would hamper your spring a bit.