One of my players has a major problem with spell foci. He presented the example of the spells Conjure Barrage & Conjure Volley. (PH p.225 & 226)

My 1st reaction was they're both ranger spells, there aren't any ranger foci.

Then I realized they Could be snagged by a lore bard, who could theoretically use a bard focus to cast them.

Here's the conundrum:

Material Component: 1 piece of ammunition or 1 thrown weapon.

Spell text: You throw a nonmagical weapon or fire a piece of nonmagical ammunition into the air...

Both spells create multiple duplicates of the fired ammunition, but if you used a focus to cast it, you don't need the material component, so what's being copied?

I suggested the bard shoots a pick from his lute like an arrow, but that didn't sell.

Would the fired projectile constitute a consumed component? If so, then no focus could be used c.f. Material PH p.203 paragraph 2.

Thoughts? Ideas?

Ammunition and thrown weapons both have a material cost, it's just non-specific on the type of either so that you can use the spell with more than just arrows.

What is your player's problem with spell foci, specifically? Just because the bard can use a spell focus to cast the spell doesn't mean that they must. They could still throw a dagger in the air of they wanted to. If they specifically wanted to cast this spell using their instrument you could just say targets are hit with a blast of cacophonous noise.

The spell doesn't say the arrow or thrown weapon is consumed or has a cost, therefore it is not consumed.

Yeah, what i was wondering about that part was whether the act of using the ammunition, that is to say, releasing the projectile constitute consumption (the projectile isn't actually consumed by the magic) in regards to the focus.  

If i cast Jump, I can always put that grasshopper leg back in my pocket, but if i have to dispose of it to cast, doesn't that constitute consumption?

I seem to remember a law that wasn't passed, but was treated as if it had been...

There is a possibility that the ammunition could break or be lost but it still required for the spell.

The ammunition is a defined material component. A spell focus allows you to ignore the material component unless the component has a defined monetary worth or is consumed in the casting.

The solution to the conundrum I'm suggesting is that the spell requires you to release the component-and that the act of releasing the component constitutes component consumption, NOT that the casting breaks or destroys it, but the release is TREATED as consumption solely in regards to the question of whether or not a spell focus can be used.

The comparative test for this solution is pretty straightforward. Do any other of the league approved spells (240 of 460 spells with material components) have a release component text without consumption text?

Quote from Drawfonaf >>

The ammunition is a defined material component. A spell focus allows you to ignore the material component unless the component has a defined monetary worth or is consumed in the casting.

 A spell focus allows you to ignore the material component unless the spell says the component has a monetary value or says its consumed. If a spell doesn't say the component must be worth X gp or says "which is consumed", a foci can replace it.

Quote from Davedamon >>

Quote from Drawfonaf >>

The ammunition is a defined material component. A spell focus allows you to ignore the material component unless the component has a defined monetary worth or is consumed in the casting.

 A spell focus allows you to ignore the material component unless the spell says the component has a monetary value or says its consumed. If a spell doesn't say the component must be worth X gp or says "which is consumed", a foci can replace it.

 The ammunition disappears at the time of casting so needs to be provided. The damage type is also determined by the ammunition used.

Nothing states the ammunition used as a component disappears, it's the barrage volley you summon that vanishes. You can recover ammunition and thrown items at the end of a fight, recovering all thrown items and half your ammunition if you spend 10 minutes searching, so nothing says that is consumed by virtue of being fired/ thrown.

Here's the component description of conjure barrage

"* - (one piece of ammunition or one thrown weapon)"

Here's the component description from create homunculus

"* - (clay, ash, and mandrake root, all of which the spell consumes, and a jewel-encrusted dagger worth at least 1,000 gp)"

See how it clearly specifies, with no ambiguity, that the spell consumes the components? If X explicitly says it does Y, then anything that doesn't say Y can be assumed not to do Y, otherwise it'd explicitly say it did

Then why were insisting that the PC use a focus instead?

Ammunition and thrown weapons clearly have GP costs associated with them. They are not listed in the spell description because if they were, the description for the material components would be longer than the description for the spell. Even with the Class Feature Variant that allows a Ranger to use a Druidic Focus, as a DM, I would still require those components to cast those spells. Just because that component is not “consumed” does not mean that it ignores the rule governing “specific GP cost for a spell components.” The character could always use a rock, and as an improvised weapon they would deal 1d4 bludgeoning damage. Saying you don’t need those components is like saying you could whack someone with a Wand and cast Green Flame Blade. 

Every possible component have GP costs associated with them unless they're things that can be found growing by the side of the road. That's why spells explicitly state a cost for components that qualify as having a gold cost. For example the spell 'Alarm' requires a 'tiny bell'. A bell has a value of 1 gp, does that mean you can't use a spellcasting foci to replace that component? No, because the spell doesn't say "a tiny bell worth at least 1 gp".

The rules are very clear for material components and foci; 

But if a cost is indicated for a component, a character must have that specific component before he or she can cast the spell.

If no cost is indicated (not inferred, indicated) it can be replaces. It's the same for consuming components:

If a spell states that a material component is consumed by the spell, the caster must provide this component for each casting of the spell.

The spell must indicate the component is consumed for it to be except from replaced with a focus. Conjure Volley and Conjure Barrage do not state a cost nor do they state the component is consumed.

Saying you don’t need those components is like saying you could whack someone with a Wand and cast Green Flame Blade. 

Quote from Davedamon >>

Every possible component have GP costs associated with them unless they're things that can be found growing by the side of the road. That's why spells explicitly state a cost for components that qualify as having a gold cost. For example the spell 'Alarm' requires a 'tiny bell'. A bell has a value of 1 gp, does that mean you can't use a spellcasting foci to replace that component? No, because the spell doesn't say "a tiny bell worth at least 1 gp".

The rules are very clear for material components and foci; 

But if a cost is indicated for a component, a character must have that specific component before he or she can cast the spell.

If no cost is indicated (not inferred, indicated) it can be replaces. It's the same for consuming components:

If a spell states that a material component is consumed by the spell, the caster must provide this component for each casting of the spell.

The spell must indicate the component is consumed for it to be except from replaced with a focus. Conjure Volley and Conjure Barrage do not state a cost nor do they state the component is consumed.

Saying you don’t need those components is like saying you could whack someone with a Wand and cast Green Flame Blade. 

I mean, you can use a wand to replace the component of 'a weapon' but you still need a weapon to make the attack specified in spells description.

 Okay, then one could cast Conjure Barrage or Conjure Volley but without the ammo/weapon to copy then there would be no effect just like your scenario with Green Flame Blade.

Yeah, working back through my logic, yeah, you could cast the spell but get no effect because you don't fulfil the steps. That does render the cost part of foci moot.

However, that's not the important part. If these were components that were considered to be consumed, then that'd result in you not being able to recover the ammunition/thrown weapon afterwards, which would be bad for thrown weapons.

I do think I'm more arguing pedantically the function of components rather than anything super constructive.

Also, sorry for the obnoxiously large quote box at the end, I swear it didn't look like that when I posted.

Yeah, something glitched there, not your fault. Are you using a mobile device by chance? It probably happened with the switching from landscape to portrait or something. 

I never argued that the spell consumed the items, all I argued were that the ammo/weapon were requirements. As I said, the caster could simply throw a rock and it would count as an “Improvised Thrown Weapon,” 1d4 bludgeoning damage.

Also, Identify requires “a pearl worth at least 100 gp and an owl feather” but it also never specifies that it in any way “consumes” the pearl. Using the same argument that you used, as a DM I have ruled that a character can continue to reuse that pearl as many times as they like, the feather however could be replaced with a focus.

Quote from IamSposta>>

Yeah, something glitched there, not your fault. Are you using a mobile device by chance? It probably happened with the switching from landscape to portrait or something. 

I never argued that the spell consumed the items, all I argued were that the ammo/weapon were requirements. As I said, the caster could simply throw a rock and it would count as an “Improvised Thrown Weapon,” 1d4 bludgeoning damage.

Also, Identify requires “a pearl worth at least 100 gp and an owl feather” but it also never specifies that it in any way “consumes” the pearl. Using the same argument that you used, as a DM I have ruled that a character can continue to reuse that pearl as many times as they like, the feather however could be replaced with a focus.

Agreed. That’s my point. I just wanted to point out that I am aware of the rules regarding “consumed” components vs. non-consumed. 

Quote from IamSposta >>

I never argued that the spell consumed the items, all I argued were that the ammo/weapon were requirements.

 That took us a long time to get there =)

So the next question would be, if the arrow used was silver/adamantine, would to barrage or volley be silver/adamantine?