Are Mule Coins Possible Without The Help Of Mint Employees?

I agree, I have been struggling to find any evidence of an employee being caught doing this though.

By the way,

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It can happen by accident - see the Australia 2000 Mob of Roos mule: https://en.numista.com/128492

That is indeed impossible, because coins are always struck all-at-once, not one side at a time in a two-stage process.

A mule happens when "the wrong die" is inserted into the high-speed coin press that they use to make coins. Both dies (the "incorrect" one and the "correct" one for the other side) strike the blank at the same time, thus creating the mule coin. Human error is required for putting the wrong die in place, and as with many "human errors", it can be done either by genuine accident or deliberately. An accident is entirely possible, as the high-speed presses are designed to take any of the dies which the mint might use to make any of the coins requested of it; the same press might be making nickels today, and dimes tomorrow. Your typical "mule" is probably made when someone simply forgets to swap out one of the dies, when production on a press changes to a different coin.

How likely a mule-causing accident can happen depends in part on that specific mint facility's inner workings and processes - how dies for the different denominations and/or different countries are stored, catalogued and accessed, and how they're taken in and out of the presses. Is it just one guy who goes to the die cupboard and rummages around for the correct dies until he finds them, or are there multiple checks with multiple people making sure it's the right die before someone presses the "go" button? The more checks and balances there are, the less likely such errors can occur, and most modern mints have lots of checks and balances in place for this exact reason. But it should be note that "less likely" does not mean "impossible". Wait long enough, and pretty much anything physically possible will happen.

Double-obverse and double-reverse mules - coins that are either two-headed or two-tailed - are much harder to make by genuine accident, as the dies for obverses and reverses are physically different in size and shape - putting an obverse die into the reverse die position is literally like putting a square peg in a round hole. two-headed/tailed coins are almost always the result of someone deliberately fooling around with dies, in a coin press that isn't the usual high-speed production press but one which can be manually adjusted to take any old die in either obverse or reverse position.

The main problem with any "Error X must have been made by insiders at the mint to make money" conspiracy theory is twofold:
(a) how do they actually catch the "error" coins after they are made, when there's no human involvement or intervention in a modern high-speed coin press, and
(b) how do they smuggle the coins back out of the mint, when the mint has lots of security screening in place for mint workers which is specifically designed to stop those workers from smuggling coins out of the mint?

This is why I've always adhered to the idea that most mint errors (at least, in modern Western mints like the USA) are genuinely errors, that enter circulation through normal channels and are detected by regular people who happen to notice them in change. I'd find the idea that a mint error is a complete counterfeit, made outside of the official mint using fake dies, to be more probable than the "mint workers did it to make money" conspiracy.

Thanks @Sap - I tried to explain that, but cam up short on the words required to do that well.

Great explanation Sap. I always learn a lot from your insightful discussions.

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