"You could always make a gun, all you needed was a lathe, some tooling, a hacksaw a file, some steel stock and a bunch of patience.... Printing a gun is just another way to get to the goal, possibly an easier one but one with its own unique challenges."

A sufficiently large quantitative change is a qualitative change. Also the debate is ultimately not about this one thing today, but about a future in which one can download and print an open-source AK-47-equivalent with only slightly more difficulty than printing a picture.

I'd contend this isn't "printing" or the definition of "making it yourself" that you'd consider here in 2011; it's a new semantic category that very few people are prepared to grapple with, least of all the law. I'd contend the law is yet to catch up with what computer programs permit people to do, it really isn't ready for how computer programs will increasingly freely impinge upon the real world. There is simply no legal category to handle this question, and many conventional ethical ones can't handle it very well either.

The only solution is to go back to first principles, but most people can't really reason on first principles.