M-28 or M-29 Davy Crockett Weapon System was a tactical nuclear recoilless gun designed to fire a small sub-kiloton nuclear projectile.
https://s3-us-west-1.amazonaws.com/h...um/nukegun.jpg
4:12 video:
https://www.youtube.com/watch?v=eiM-RzPHyGs
Previously:
https://www.homemadetools.net/forum/...969#post133864
https://www.homemadetools.net/forum/...188#post121171
https://www.homemadetools.net/forum/...042#post149302