Depending on caliber, they can ragne from 4-28 grains.
They are about the same, depending on the pistol. C02 has a tendency to be a little louder on certain pistols but not much difference.
It would help if you stated the model and the condition of the pellet gun. Without some information it is not possible to answer you.
A 6mm BB gun pellet will weigh about 0.20g ----
It weighs 43 OZ or 2.68Lb Made between 1966-1983 .22 Caliber modeled like a Ruger pistol
It depends on the model and the caliber of the Pellet gun.
There is "NO" best pellet. See the link below for much greater information about pellets
I think you mean pellet gun. That is a gun that fires a small lead pellet but does not use gun powder. It uses compressed air or compressed gasses to push the pellet.
What condition is it in. That determines the value
As little as $15 and as much as $1,500 or more, depending on what you want.
A pellet gun is not adequate for protection, and will get you arrested.
It all depends on the model and who made the pellet gun. I suggest that you re-post the queston with the model and make of the pellet gun to get an answer.
Any pellet gun should be handled like a real firearm. Yes you can be killed with a pellet gun under the right circumstances.