Crazy slingshot guy builds one:
Hmmmm unregulated auto receivers in Germany. Who knew? He must really love slingshots if he picks those over auto firearms. What a waste of a auto receiver though haha man.
My first thought was that it looked really front heavy, but in the comments he addresses that and says that front part is made out of really light wood similar to a cigar box. There are a few different expensive “cross bow” type AR-15 upper receivers on the market you can google if you’re in the market for something for that platform that shoots arrows.