The hole using someone elses machines to make weapons is still really fuzzy in my opnion. The way I understand there letter is you can not walk into a machine shop hand them 25 dollars and press a button wait and have a finished firearm kicked out. But you can give the shop $25 dollars rent to use there machine for 2 hrs write your own CNC code put your chunk of aluminum in the machine and press start. But like I said that is my understanding. And it a damn blurry one at that.
The 2015-1 ATF ruling basically only applies to gunsmiths or those in the business of firearm manufacture.
More generically 'push a button' stuff is more or less "who made the firearm". Whoever bends a blank into the shape of a receiver is the person who made that firearm. If you're just a joe shmoe with a vice and jig - all this means is make sure your buddy walks over to your tools and presses the button / hammers the plate down / turns the vice. But none of that has to do with 2015-1 ... that was just pre-existing law (or regs, whatever).
There might be some fun questions about cnc / 3d printing - but whatever.
I don't believe any of the above have anything to do with ammo, though. It's all very clearly spelled out as firearms themselves.
The topic of making ammo for someone else if they provide the materials and you don't get anything out of it (money, left over material, any other in-kind value) is ... well... you gained nothing from it. In fact you lost stuff in it. Time, wear on your machines, etc. 06FFL relates to business ventures. You're not receiving anything so ya prolly don't need the 06FFL. A signed waiver and still having an insurance policy is prolly a good idea. Look at the guy sueing some coffee place because he got burnt by the free coffee he was receiving every day.
Someone paying you to make use of your gear to make
ammo is not addressed as far as I know. Now, if they made something illegal and you knew about it - that'd be a problem (see also: a titanium wire / nail / electrode in the middle of a pistol round - aka AP ammo). As a possible corollary, you would need to look at it like a pottery place letting folks use their turn wheels and autoclaves.... I think.
As an aside - SFG and I do have folks pay us for instruction on reloading - and during the course of the class, students do end up making 10-15 rounds of ammo on our equipment
