@metal-brain said
You might need springs and some fasteners and a firing pin so I suppose you are right, but how hard is it to get those?
"Parts like fasteners and springs that have the critical task of holding everything together were not – so were the barrel and receiver, as well as trigger and firing pin.
Barrel and receiver were fabricated in aluminum using a process known as direct metal laser sintering (DMLS) while trigger and firing pin were printed in 4340 alloy steel. DMLS, btw, is kind of like 3D printing, except that high-powered precision lasers were used to heat particles of powder to below their melting point, thus essentially welding the fine metal powder layer by layer until a finished object was formed.
Of course, the entire process was not as simple as print-and-assemble; it has a few post-printing processes too, like in the case of the aluminum receiver and barrel, machining and tumbling were required and in the case of AM components, they had to be snipped from the build plate, the support material removed and whatnot. All told, 5 hours of post process was required for the barrel and receiver alone which itself took around 70 hours to print. The grenade launcher itself took 35 hours to print on a single build plate. The time and cost involved are significantly lesser over conventional methods which would take months and costs tens of thousands of dollars."
https://mikeshouts.com/u-s-army-3d-printed-grenade-launcher/
Know a lot of folks with high powered precision lasers in the garage?