In this video you'll see how I built a multishoot air rifle. This video shows the building of the trigger and the hammer, but the breech is a Crosman multishot breech. It uses a 0.5 L tank, gets 40 shots at 35 joule, 1200-1250 FPS using 7.8 grain pellets. With heavier pellets would probably be around 40-45 joule.
Fund my projects: https://buymeacoffee.com/pcpairgunschannel
Valve: https://s.click.aliexpress.com/e/_DdrMYVb
Bottle: https://s.click.aliexpress.com/e/_DDIDqPJ
Video of valve & bottle: https://youtu.be/Q_uX9aRXuj0
Parts:
Crosman 2240 breech: https://gmaccustomparts.com/multi-shot-breech-34
32mm OD aluminium tube: https://s.click.aliexpress.com/e/_DeHHpTV
Trigger spring: https://s.click.aliexpress.com/e/_DEdXDVv
Stainless Steel sheet: https://s.click.aliexpress.com/e/_DCpjwx1
Spring for hammer: https://s.click.aliexpress.com/e/_DDfQ5qT
2.5mm steel rod: https://s.click.aliexpress.com/e/_Dk9NG3v
Aluminium plate for trigger housing: https://www.aliexpress.com/item/32961679695.html?
M4 Breech screw: https://s.click.aliexpress.com/e/_DnLuQu3
20mm Steel rod: https://s.click.aliexpress.com/e/_DdECHQ3
Grub screws: https://s.click.aliexpress.com/e/_DD6b0SX
M4 Round connector: https://s.click.aliexpress.com/e/_DEngxNZ
M3 Breech screw: https://s.click.aliexpress.com/e/_Dn1VNCR
O-ring: https://s.click.aliexpress.com/e/_DcjmAQn
M4 Countersunk screw: https://s.click.aliexpress.com/e/_Dcymir1
Drill bits: https://s.click.aliexpress.com/e/_DC7jEJv
Sanding stone tool: https://s.click.aliexpress.com/e/_DeiInDp
Thread taps: https://s.click.aliexpress.com/e/_DCrUV5p
Sandpaper tool for drill: https://s.click.aliexpress.com/e/_DEgRCQP
Rotary file: https://s.click.aliexpress.com/e/_DEbC4mX