SARCO has some of the parts listed. .22 Suppliment Chamber, Belt Adaptor & Clip These parts are sold as a set of 100 for $150.00.Activating Piston ( Floating Chamber) $75.00.Bolt $200.00. I am not sure if the bolt is complete or not. A standard drive spring can be cut to 66 loops and used. They also have Firing Pins for $45.oo.You do not need the Chute. Other bolt parts are 308 or 30-06 (standard parts). Barrels are hard to find. There are other parts that go with the barrel and are not always with them. ( Nut, Booster or end, Chamber for the Activating Piston) I had a guy make my barrel and these parts for me. I also made my front Cartridge Stop from a blank stop. It uses a standard 30-06 cloth belt. I found links were to hard to use on mine. In the book Hard Rain (Frank Iannamico) on page 130, are photos of the conversion kit. I am still working out the bugs, ( a burr on the bolt), and a weld broke on the booster, so I braised it rather than rewelding it. I put a brick of 22 shells through mine today and not many problems. Every time I go out it works better.
Have fun with your project and good luck. CCKW