This question has 2 parts, but any information that provides context to help me understand how these weapons compare is appreciated.
Primary Question: Would it be considered "balanced" to award a player with a +2 Longbow, instead of a +2 Greataxe?
Secondary: How does the possibility of magical ammunition play in to this decision?
Context
I am running a published campaign and the final encounter of this "chapter" provides a +2 Greataxe. All the characters are finesse-based (or a Moon Druid) and thus I was hoping to change this out for a Longbow for our ranger.
All the other characters have received magic items by this point except the ranger. The ranger does, however, have three +1 arrows. I am concerned that the +2 Longbow might be stronger than intended for the character level (5), and the magical ammunition compounds that, even though it would only provide a temporary boon. Campaign wise he will not receive any additional magic ammunition until level 13 or so, and it too will be of limited quantity.
Does the range bonus, and ability to shoot magic ammunition, make this longbow considerably more powerful than the Greataxe it replaces? If so, should this be mitigated by allowing a +1 Longbow instead, or requiring a gold component for "trading" in the Greataxe for a Longbow?
Lore-wise for this chapter of the campaign there is a reason (although its not really story progression relevant) for the actual treasure to be an axe. The character would trade this axe into a collector (it contains a specific master craftsmen's insignia) and would receive a +2 Longbow as a reward. This would be a minor role-play element in-between adventures.