Remix with my addition of printable pins. No longer need to buy the 2mm/3mm steel pins or BB. I printed my pins from PPS but PC should also hold up. You will still need to buy the 5mm compression springs and #8x3/4" screws.

Supports are painted where needed. 3 materials are used. ASA, TPU, and PC. The ASA parts could be replaced with PLA without loosing too much functionality.

Assembly instruction given as pdf in other documentation as well as the source file. A slight change is retaining the buttstock with most buffer tubes. The locking pin length/hole posistion is augmented so the stock cannot be pulled off while the locking pin retaining pin (2mmx22mm) is in place. One needs to slide the locking pin in the stock, use the 3mm pin to join the level and locking pin, slide over the buffer tube, then install the locking pin retaining pin.