Here is the bottom line in the schools, your own home be your own homes. There are laws forbidding the manufacture of items intending to be used as, or as parts of weapons. There are laws forbidding the manufacture of look alike weapons. There are laws forbidding the manufacture of drug paraphenalia. These laws apply to school programs and on school grounds. These laws have been set up by liberals according to many in regards to gun items, and conservatives in regards to drug paraphenalia. Same applies for tobacco paraphenialia (which is the common "out" tried on me all the time).
Teachers are required by law to report suspicious activity in the shop, or in student interactions. There are 13 dead students at Columbine that may have been served well by better reporting (that is my editorial).
A student can make a hammer. The intent of the project is as a tool for a machinists box. If the kid goes out and beat the heck out of some other student, the intent protects me in a lawsuit. A student makes a firing pin for a gun. The intent is for a gun. If it is made clandesdine, I am in a pickle to try to explain this. Most likely I am out of trouble on the surface, but by being "not on top of things", I am still in some binds.
I only talk from a school standpoint, but also stand by the other liability statements I listed for home shop machinists.
Lawyers run the world, and sorry to say, I am not the one who wishes to change the world by being the guy in jail who will also be soon forgotten the next hot topic that comes up.
I would not spend as much time as I do here if I thought any of you were anything less than very intelligent. I admit it, if I have a stick, I am not afraid to stir that pot of poo. I like it when the threads get big responses, the different input is food for the brain. SO, KEEP IT UP - Eh!
As for psychotic LCB's - it is a poor excuse of a Human being that looks to blame anyone or anything else for a imbecile and their thoughtless actions - the only one at fault is the perpetrator. Transferance of blame is not justification for a diliberate act of terrorism.
You might be allowed to make a one off item for your own use, but you also may not be allowed to leave your house with it. Depends on state and local law.
I doubt that any BATF agent or office would give you a letter of permission-they just don't stick their necks out like that.