Does the spell Swift Quiver RAW only apply to bows/arrows?

Question

One of my players wanted to use the spell swift quiver (PHB p. 279) with a magitech revolver-style weapon. As the weapon isn't more powerful than a similar ranged weapon would be with the spell (1d8+Dex base damage, 60/240 range) I'm inclined to allow it.

However, in coming to this decision, I noticed that the spell specifies that the ammunition must come from a quiver rather than any ammo container, so not a crossbow bolt case or a bag of darts or a magazine for bullets.

The equipment section specifies in its description that a quiver only holds 20 arrows. Which may restrict the spell to only arrow/weapons that fire arrows.

With the traditional image of a rapid-fire archer being a bow user it is possible that this potential RAW reading is also RAI.

That said I cannot find specification for which ammunition an ammunition-requiring weapon expends, only that you must have some ammunition to spend for the attack. RAW it seems that a sling can fire arrows (which makes no logical sense to me).

So two odd cases of RAW that might cancel each other out, rendering my question moot: swift quiver only applies to arrows/all ammunition weapons can expend arrows.

How would you read this?

Answer 1

First off, Swift Quiver doesn't only apply to arrows

Components: V,S,M (a quiver containing at least one piece of ammunition (PHB 279).

Emphasis mine. The spell only requires the quiver and ammo, since ammunition includes arrows, blowgun needles, sling bullets etc... all types of ammo can be replaced by Swift Quiver (assuming the container counts as a quiver, which I personally would be very generous in defining).

However, you may want to be aware of weapons with the Loading property:

Because of the time required to load this weapon, you can only fire one piece of ammunition from it when you use an action, bonus action, or reaction to fire it, regardless of the number of attacks you can normally make (PHB 147).

Depending on if the revolver is a loading weapon, the player may only be able to shoot once per turn (barring some feat akin to Crossbow Expert allowing them to ignore it).