Ammoland by Dean Weingarten 10/24/2019
In most “3D printed†AR-15 type rifles, only the lower receivers are 3D printed for the platforms they are on. The lower receiver holds together the fire control system. There is little mechanical strength needed. Upper receivers have not generally been printed because they are easily available in the United States. They are considered a firearm part, like a buttstock, a bolt, sights, or a magazine. They can be purchased over the counter or through the mail as part of ordinary commerce.
The rifle pictured in the Twitter post above is different. It is not using an AR-15 lower or an AR-15 upper. It is labeled a “bolt actionâ€, that is a manually operated rifle.
This design appears to take standard type AR-15 magazines. It should be easy to alter the design to take different magazines from different platforms. Numerous magazines have been successfully printed with 3D printers, some with plastic springs.
The ingenuity if the design is interesting. Some features can be deduced from the picture and some from comments made on Twitter.
It was claimed the design has been fired once, successfully.
More:
https://www.ammoland.com/2019/10/3d-printed-bolt-action-223-rifle-successfully-test-fired/#axzz63SvA3q5R