Materials:
- BB rifle barrel, 6,03 mm ID encased in a 1 cm brass tube
- green gas container
- schrader valve
- piston valve inside a 1/2 T
- ball valve
- blowgun
- wood

It's still a work in progress as I only have time during the weekends.
As you can see, at the moment the barrel assembly is taped to the gas container until I manage to figure out how to improve my wood carving skills

Operation is quite simple: turn off the ball valve, pressure the chamber through the schrader valve, pull the barrel, insert the BB
push the barrel back in place
turn on the ball valve and ready to fire.
I hope to finish the loading mechanism this weekend (that is attach a pin to the barrel so I could manipulate it easier) and the buttstock
and then I can sight it properly and show some damage.
At 7 bar a 0,25 g plastic BB almost penetrated a 3 mm solid aluminium plate from 10 m.
Feel free to help me improve the BBinator

OK, some damage pics:
7 bar, 0.25g BB plastic, distance 2 m
front:

The dent in the upper part is from a miss (yeah, I wear glasses

back:

and bottom:
