You need Chainmail for morale too. It's referenced all over, but the mechanic isn't in OD&D. You can infer something akin to it that works from the NPC reaction table, but my opinion has always been that it was an oversight. Either way, there's no explanation on how or when to check it, as I recall.
As for missile ranges, you could get that from any miniatures wargame, or a book. It's not a Chainmail-specific procedure.