No it's a pump and no C02 is required
No it's a spring piston system
The 15XT has a built in seal.
I would contact Daisy directly and ask them See the link below
Take the High Road - 1980 1-822 was released on: USA: 25 February 1991
If the co2 cartridge is full unscrew the back slowly until all vapor is gone, then just unscrew the back all the way off and it will slide out.
I think when they receive carbon dioxide
822
I would suggest contacting Daisy air gun directly through their Customer Service. See the link below
822 the nearest ten
Yes they take up CO2. Then it is reduced to glucose
822 can be divided evenly by: 1, 2, 3, 6, 137, 274, 411, 822
822 is a Composite Number