Color me highly skeptical.
While I don’t doubt that many parts can be printed out and even work, I very much doubt the receiver and barrel and other parts that must withstand the pressures of ignition will have the strength to do so. Just because something is in the right shape doesn’t mean it will have the physical characteristics needed.
Now when we get to the stage on personal nano-material assemblers it will be a different story...
Just to let you know ... you don’t have to print in plastic or epoxy. There are “printers” aka rapid prototyping that work with metal. Also, the receiver in an AR platform does not really undergo that much stress. Barrel and chamber - yes. But the receiver, not so much.
What has the libs collective panties in a knot is that the “gun” (actually the receiver according to the ATF) can be owned and manufactured by anyone WITHOUT REGISTRATION. Their panic is that everyone could have a gun the the government does not know about!!!!