the trigger gets pressed by a finger for every shot.
Actually, that's not correct. The trigger presses ITSELF against the shooters finger. And that's the problem.
If the finger was doing the work (or the shooter was pulling the trigger forward into the finger) it would be legal. Since the gun is doing all the work and the shooter isn't moving it's not.
Your argument is based on this phrase: "by a single function of the trigger" and posits that because the trigger is functioned for each shot that the Akins device is legal. What you're missing is that the law is meaningless (it doesn't actually create any sort of a restriction) if it is legal to create a system whereby the gun functions the trigger by itself or can function the trigger by itself without animate input after the first shot. Clearly the Akins device falls into this category as do machineguns.
The position of the legal system in this country is that laws are not meaningless. So if there are two interpretations of the law and one makes the law meaningless that interpretation will not be employed. In other words, the courts will not accept an interpretation of the law that makes the law pointless and therefore your interpretation of the law will be considered invalid by the courts.
Laws are more than just a strict, literal, word-for-word interpretation of their text. When a case is tried, the intent of the law is considered, not just a literal word-for-word read of the text.
Yes, the law says "single function of the trigger" but the law isn't worded that way in order to ALLOW guns that somehow cleverly "function" their own triggers for each shot but rather to OUTLAW guns where the SHOOTER does NOT "function" the trigger for each shot.
The BATF's final ruling on the Akins device is consistent with the law. It is not based on an improper interpretation, an unreasonably narrow interpretation, nor a stretched interpretation of the law.
The law is silent as to triggers being turned into sears even when bumping up against a finger.
That's the point. The law is NOT silent on the topic. It is general enough to outlaw both conventional machineguns and less straightforward designs like the Akins device which may be internally different but function externally identically for all practical purposes.
Congress could re-write the law to prohibit bump-fire devices, or redefine bump-firing. It hasn't.
They don't need to. The current law is more than sufficient. It clearly allows bump-fire and clearly outlaws devices like the Akins system.
Look, I'm no fan of the BATF or the NFA. Both need to be done away with. But as of right now, they are reality and we have to learn to deal with that reality. Trying to push a personal interpretation of a court-tested 70 year old law that essentially makes the law meaningless isn't dealing with reality and it can only cause confusion.
The Akins device is NOT a bump-fire device because it functions like a machine gun. A bump-fire device does not function like a machine gun--there is a clear and critical difference between a bump-fire device and a machinegun. With a machinegun (or the Akins device) you pull the trigger and hold your finger still and the gun continues to fire without any other input from you. In a bump-fire device you have to pull the gun forward against your trigger finger for each shot, functioning the trigger for each shot.
Very simple, open and shut. The crime is that the BATF botched their initial ruling so badly.
Even if you can't see that, it should be obvious that by adding a very simple secondary trigger (see my comments about adding a hinged device in a previous post) that you can very easily convert an Akins equipped device into a machinegun that meets even the strictest possible definition of a machinegun. And by law, a device that is readily converted to a machinegun is also a machinegun.