Kirk Freeman
Grandmaster
3-D printed upper in .22lr.
(Video demonstrating it being test fired)
https://www.thefirearmblog.com/blog/2019/08/09/3d-printed-ar-15-22-caliber-upper/
(Video demonstrating it being test fired)
https://www.thefirearmblog.com/blog/2019/08/09/3d-printed-ar-15-22-caliber-upper/