Silly Unlimited Gold idea.

[Kasz]

The Idea.

Splitting on works on bows and crossbows. Make a bolt out of solid platinum. Fire it at target dummy but miss on purpose... collect the two bolts. Repeat.

If you can get it on a sling then use it with coins.

The Problem.
Ammo "breaks or becomes unusable" if it hits, or has a 50% chance if it misses. This is DM dependant but I'd say as long as you collect all the pieces of platinum it doesn't matter if it's reusable, just melt it down for the platinum... If neither are resuable use "mend" or "Repair light damage".

If there's a way to enchant a weapon so the ammo is always reusable, such as "returning" arrows or something because both arrows have all the properties... both arrows would return.

A Splitting Bow with a Returning Platinum Arrow = Infinite wealth?

(I know there are ways of doing this without questionable rules such as flesh to salt on cows and taking ladders apart and selling the timber... but this doesn't mess with supply and demand as much... Platinum bars are currency so it's more like counterfeiting.)

[daekken]

Scary...

[Maat Mons]

If there's a way to enchant a weapon so the ammo is always reusable, such as "returning" arrows or something …

Raptor arrows (Magic Item Compendium, p56) work like that. 

[kitep]

Just fire it at a monk that can catch the arrows 

[Gazzien]

If there's a way to enchant a weapon so the ammo is always reusable, such as "returning" arrows or something …

Raptor arrows (Magic Item Compendium, p56) work like that.

Despite always being mentioned, they're a relic and there are explicitly five of them. IIRC. That might be from their entry in Complete Divine, though...

And I don't think you can just make more? I was always under the impressesion that despite having lists costs, you couldn't make relics without the god's help.

[zook1shoe]

Besides the fluff, that's awesome! Gain ~$6k a shot

[Maat Mons]

You can't buy relics; that's true.  Magic Item Compendium's description of relics says you just need to meet the prerequisites to craft them, so divine intervention isn't necessary.  It also says there should be role-playing consequences for acquiring a relic by ant means, including crafting, so it's still probably a big hassle. 

A cheaper and easier alternative would be arrows with hardwood shafts (Dragon 330, p92), which have only a 25% chance of breaking on a miss.  So, on average, you'd get 1.5 arrows back for every one you shoot.  The arrowhead can still be made of whatever. 

From a RAW perspective, one issue is that the writeup of platinum weapons (Magic of Faerun, p180) never explicitly mentions ammunition. 

[Kasz]

Well, as a two man set up the Monk option works great. He just needs a way to get a second arrow catch per round. This would work best with expensive ammo. Any expensive ammunition works, gold, platinum, enchanted with slaying or whatever. If you can't get a second snatch arrow per round then you basically have a 50% chance of making money that round...you always break even. 75% if you use hardwood.

If you can swing raptor arrows...then I guess you've just worked out how to produce relics at a rate of 1/round.

I guess you could buy a raptor arrow for 6k (or craft / otherwise obtain), spend 100k enchanting it (1/50th cost because ammo). Then spend 9 rounds firing it at the wall and voila... you have 10 arrows that cost 106k each. more than enough for a full attack even with haste/rapidshot. Then I guess you can just sell them for profit.

[Roxoff]

Ahh if only.  Let me just reach for my DM's hat a moment...

Right.  My understanding is that the 'splitting' quality means that any arrow fired from the bow is split into two and each part then goes on to do normal damage for the arrow if it hits - it's a property that allows you to do double damage with your missile weapon.  The problem here is the 'split into two parts'.  What you effectively do is have two half-an-arrows that hit and do normal damage each.

if you were to cast a platinum arrow and attempt to fire it from such a bow (apart from the physical problems with firing a heavy metal arrow in the first place), you would then end up with two half-an-arrows when it landed.  In fact, if it were my game you were trying to do this in, I'd just let you know that the two parts produced contained very slightly less platinum than you started with due to loss during the splitting process.  On, and I'd tell you missed because the arrow was too heavy and only flew about a foot before landing on the floor with a loud clang.

Looking at this from a wider perspective, if you can duplicate your precious metals this way, then you wouldn't be the only one to be able to do this.  Very few would actually have the capability, but it wouldn't need many people producing unlimited platinum to make platinum worthless as it would be so abundant.

[Raineh Daze]

This leads to the strange outcome of infinitesimally small arrows that can all be handled, shot, and do the same damage, which makes less sense to me than abusing conjuration and transmutation to get infinite arrows.

[Kasz]

Well, it's titled "silly" for good reason. I wouldn't let it fly in a real game either.

Based off the wording of the splitting ability.

SPLITTING
Any missile fired from a splitting weapon, or an arrow or bolt enchanted with the splitting ability, breaks into two identical missiles before striking the intended target.
Description: V-shaped engravings adorn a splitting weapon or splitting ammunition.
Activation: The splitting ability of a ranged weapon (must be a bow, crossbow, arrow, or bolt) only functions if its wielder has the Precise Shot feat.
Effect: Any arrow or bolt fired from a splitting weapon magically splits into two missiles in mid-flight. Both missiles are identical, sharing the nonsplitting properties of the original missile; for example, a +1 splitting arrow splits into two +1 arrows in mid-flight. Both missiles strike the same target. Make a separate  attack roll for each missile using the same attack bonus.
Aura/Caster Level: Moderate conjuration (creation); CL 7th.
Construction: Craft Magic Arms and Armor, Precise Shot, arrowsplit, +9,000 gp, +720 XP, +18 days.
Weight: —.
Price: +3 bonus

So based off the wording, one missile splits into two missiles. This has 2 interpretations. 
1. The missile becomes two halves of the original, becoming two missiles.
2. The missile duplicates the original, becoming two missiles.

The second is supported by the bolded text in the quote, as it reads in the example the arrow becomes two arrows, not two halves of an arrow. Also I imagine half an arrow would do less damage and have less range/flight capability.

Also the text from Arrowsplit, the spell it's based on is thus:

This spell is cast upon a masterwork arrow or bolt, causing it to split in mid-flight into 1d4+1 identical masterwork arrows or bolts.
All the missiles strike the same target, and you must make a separate attack roll for each missile.

the target is an arrow or bolt, the effect is identical arrows or bolts, hinting at duplication not separation.

I did note that as platinum is currency it should devalue less than most trade goods... but if you find that occurs then cloning raptor arrows (as only 5 exist) or magical arrows made from darkwood (that get used up when fired) would still work.

We go to a heavily orc infested area with a Darkwood arrow of Orc Slaying for example, assuming we bought 1. The arrow costs 2,282 gold and 1.5 gold to be made out of darkwood. So 2,283.5 gold.

I fire it at monk friend who has a crystal of greater arrow deflection so he can deflect an extra arrow should it hit him. He catches one and the other is deflected and has a 25% chance of being destroyed.

We do this 20 times, we keep our original arrow and 15 duplicate arrows survive, we now have 16 arrows. We have now made 34252.5 gold from our initial investment. OR we use the arrows to complete quests with ease.

Like I said, silly trick, probably shouldn't try to sneak it past your DM but if you want to play an archer without worrying about ammo... or if you just want to have special arrows for every occasion despite buying them each once only... then it might work

[Roxoff]

I found this description of arrowsplit the spell.  it states that the arrows are destroyed even if they miss...

Judging by that description, you can make as many platinum arrows as you want, but you don't get to keep them afterwards.  Seems like a great way to destroy perfectly good platinum to me.

[Raineh Daze]

If the arrow is caught, it hasn't exactly missed. Semantics!

[Roxoff]

If the arrow is caught, it hasn't exactly missed. Semantics!

it says 'The projectile is destroyed even if it misses its target.'  - so the arrow is destroyed.  It doesn't say destroyed only if it hits or misses the target.

[Raineh Daze]

No, that just means the 50% chance of an arrow's being destroyed when it misses goes up to 100%. If you use this, the arrow isn't destroyed, because that wouldn't make sense. The 'destroy on miss' thing doesn't apply, and neither does 'destroy on hit'.

[Kasz]

They definitely should have added that clause in the splitting description.

Well this only works then if the monk can catch more than 1 arrow a round, as catching is neither hitting, nor missing. You'll notice the clause in Snatch Arrows;

When using the Deflect Arrows feat you may catch the weapon instead of just deflecting it. Thrown weapons can immediately be thrown back at the original attacker (even though it isn’t your turn) or kept for later use.

You must have at least one hand free (holding nothing) to use this feat.

It implies when you catch items they can be kept, they do not suffer the destroy chance for missing, therefore they haven't "missed" they've been caught or snatched. (I know it states thrown weapons in the sentence, but it's the deflect arrows feat.)

As a side note, if you perform this trick in public (firing an arrow that splits into two that a monk then catches with both free hands) you'll probably get some side cash based on your Perform(Street performance) check.

[zook1shoe]

It'd be less broken if it was worded like Arrowsplit, which turns a MW into 1d4+1 MW arrows. This avoids any tricks w magic arrows. But it does potentially give you free arrows on misses.

Arrowsplit + Splitting Elven Double Bow (or double xbow) = 2d4+3 arrows

[Kethrian]

No, that just means the 50% chance of an arrow's being destroyed when it misses goes up to 100%. If you use this, the arrow isn't destroyed, because that wouldn't make sense. The 'destroy on miss' thing doesn't apply, and neither does 'destroy on hit'.

Ah, but the wording of the spell, "destroyed even if it misses its target" indicates that regardless of the final result, the ammunition gets destroyed.  It merely clarifies that this trumps even the normal ammo recovery chance.  Meanwhile, the wording of the feat, by RAW, only lets you keep thrown weapons, and has no effect upon ammunition.

[Raineh Daze]

No, that just means the 50% chance of an arrow's being destroyed when it misses goes up to 100%. If you use this, the arrow isn't destroyed, because that wouldn't make sense. The 'destroy on miss' thing doesn't apply, and neither does 'destroy on hit'.

Ah, but the wording of the spell, "destroyed even if it misses its target" indicates that regardless of the final result, the ammunition gets destroyed.  It merely clarifies that this trumps even the normal ammo recovery chance.  Meanwhile, the wording of the feat, by RAW, only lets you keep thrown weapons, and has no effect upon ammunition.

Eh, I don't buy that logic. It assumes a binary state--hit, with a 100% chance of destruction; miss, with a 50% chance of destruction. So it's just overriding the percentage. 'Caught' is not an option.

Also, the feat does work with ammunition. 'When using the Deflect Arrows feat'. It doesn't specify when using the Deflect Arrows feat with a thrown weapon. Presumably, you're not expected to do anything with an arrow you caught.

You've caught it, so it didn't hit. No destruction chance. You've caught it, so it's not missed, either. No destruction chance. Not destroyed.

[Kethrian]

The description of ammo destruction written in the PHB assumes that binary state, as it only mentions the two results.  The spell does not, for it does not mention anything specific about when the arrow hits or is caught or any result other than "even if it misses".  Even is an all-encompassing word, not a binary one.

As for the feat, it clearly only allows you to catch weapons, not ammunition.  If you follow the link to what is listed under "ranged weapon", arrows (and ammunition in general other than shuriken) are not on the list at all.  So, by RAW according to your link, both feats are a misnomer, because they clearly have nothing to do with arrows.