Belt-fed 12-gauge upper receiver. 0:38 video:
https://www.youtube.com/watch?v=1PRAjroxlJI
Previously:
https://www.homemadetools.net/forum/...204#post172632
https://www.homemadetools.net/forum/...391#post146608
https://www.homemadetools.net/forum/...133#post172405
https://www.homemadetools.net/forum/...127#post125970
https://www.homemadetools.net/forum/...835#post171223
https://www.homemadetools.net/forum/...877#post105666
https://www.homemadetools.net/forum/...986#post137710
https://www.homemadetools.net/forum/...498#post162332
https://www.homemadetools.net/forum/...700#post159496
