At the moment, sure, there's still plenty of hype included in the do-it-yourself weapons manufacturing kit. Evangelists for 3-D printing are quick to note that it is still a lot easier to buy a gun (or steal your mother's AR-15) than make your own from scratch. Moreover, experts in gun technology caution that an assault rifle assembled solely from plastic parts extruded from your typical 3-D printer today would be highly likely to self-destruct after a single shot, if it worked at all.
But the technological frontier moves awfully fast. The cost of 3-D printing is plummeting even as technological capabilities soar. There seems little doubt that we are witnessing the maturation of an extraordinarily disruptive technology with incalculable consequences for the manufacturing process of all kinds of products. Perhaps not today, but almost certainly tomorrow, the code to 3-D print your own gun will be as shareable as MP3s. Outmoded legal approaches to restricting gun ownership may not apply.