It's always a "This guy told me about his cousin's neighbor who was at a show and saw..." story. No one can ever remember exactly where, when, how, etc..

Please, if this is really true, let me know. I'd love to study the design.

Again, I have worked in R&D with composites and ceramics, and I know all of the challenges. A lifelong professional colleague worked in small-arms initial ballistsics R&D and we spent many a ponder on "blue sky" dsesigns. Very few of them were even remotely feasible.

(Trivia, al-la Ahnold: If you consider the time-averaged impulse generated by the rapidly repeating recoils as rocket thrust, you can quickly calculate that firing a mini-gun from the hip (Predator, Terminator) can be an interesting experience. That's because depending upon caliber, rate of fire, and ammunition type, the impulse/thrust generated by the recoil can exceed the weight of the operator plus weapon & ammunition load. Depress the muzzle below horizontal and squeeze the trigger and you get a short (while the ammo lasts) powered flight, with a rather rough landing.)

As to getting the tech right, this subject is not a "cause for concern" as stated in the article, because it is implausible to the point of silliness. Therefore, it is "technical" nonsense.

Frightening people about a very useful technololgy with tech-sounding prose does a disservice to scientists and engineers everywhere. I'll leave the political aspects to others.

(More tech trivia: Dr. S. validated my observation about ceramic barrel / cyclinder inserts and their failure. Available composites generally do not have a high enough Young's Modulus to prevent barrel surround expansion at firing. Often even on the first firing, the insert expands, the ceramic cracks, and a shotgun patteren of barrel insert fragments follows the projectile downrange. Fine for an assissin's one-shot, but hardly practical for a service pistol. It would be a lot easier to arm said assassin with a composite / ceramic mini-grenade that would have a surer effect.)

Lastly, Google "Badass Lego Guns". Lego-brick-firing pellet guns built with Legos. They are a stitch.