With that composite one could make a firearm.
I’ve heard of those printers but had no idea they’d progressed so far. Thank you for the explanation!
Heat it, it will soften and warp. It's not terribly resistant to abrasion. Its tensile strength is nowhere near that of aluminum, much less steel.
A printed plastic AR lower, with judicious use of metal inserts on bearing surfaces, might have a useful service life. An upper would likely fail after a few dozen rounds (if that). A barrel or bolt would be destroyed by the first shot.
I hope somebody is working on a printer that uses metal powder instead of plastic ... print it then sinter it. That process might make truly useful parts for high stress machines like firearms.