Not designed for full auto modification.
Benjamin model EB22. Crosman model 2240. Benjamin Marauder Air or C02 Pistol. All 3 of these are .22 cal C02 air pistols, There are several others but they are spring or pneumatic not C02 systems
Most all C02 air guns use the common 12 gram C02 cartrage.
It is a pistol that fires BBs or Pellets that are powered by Air or C02, NOT Gunpowder. Some countries consider them Firearms some do not consider them firearms.
Take it to a professional who specializes in air weapons.
It will shoot pellets or bb's. They normally use an air cartridge.
This would be one of the best " Feinwerkbau P44 Match Air Pistol "It will cost you around $1,850 and an additional support charging system of around $400 to charge it with air.
Semi auto air guns are driven by C02 gas. when the trigger is pulled some of the C02 not only fires the projectile but drives gears that get the next pellet or bb in line to fire the next projectile.
There are several companies that make both C02 and Air pistols. For obvious reasons they don't tell each other how many they sell. So there is no overall record of which one sells the best.
There is "NO BEST" C02 pistol per shot. Each pistol reacts differently and is effected by Outside temperature and how fast the trigger is pulled. Some pistols use some of the C02 to make the Blow Back work so they will use a little more C02 than a non blow back Air gun. you can expect to get around 40 to 50 good shots from a cylinder after that the pressure will degrade. Rapid fire also effects the cycle time of the gun and this effects the pressure in the cylinder.
Range is dependent on several conditions. The size and weight of the BB or pellet. The power plant in the pistol. C02, Pump, Spring or PCP. The temperature, length and type of barrel, and finally wind. All of these effect the distance an air pistol can shoot. It is different for each model.
Benjamin Marauder PCP .22 Cal pistol using C02 not air. Or the Airforce Talon using the short barrel with full Shroud and C02 power supply. The Marauder comes in both a pistol form and a rifle format. Both will cost you around $390 for the pistol and $470 for the rifle. The Talon comes in a rifle format only and can cost as much as $1000 with accessories
Yes it would hurt and depending on your clothing it may or may not penetrate your skin.