Paintball guns
A paintball marker, also known as a paintball gun, is the main piece of equipment in the sport of paintball. Markers use an expanding gas, such as carbon dioxide (CO2) or compressed air, to propel paintballs through the barrel. The term "marker" is derived from its original use as a means for forestry personnel to mark trees and ranchers to mark wandering cattle.
The muzzle velocity of paintball markers is approximately 90 m/s (300 ft/s). While greater muzzle velocity is possible, it has been ruled unsafe for use on most commercial paintball fields. When paintballs hit an object at high speed they have potential to cause damage; a paintball colliding with human skin may cause bruising or further tissue damage. However, the damage depends on the paintball's velocity, its impact angle, and which part of the body it hits. Because of the potential for soft tissue damage, players must wear masks to protect the eyes, mouth, and ears when barrel blocking devices are not in place.
Most paintball markers have four main components: the body, hopper, gas system (or air tank), and barrel.
Paintball markers fall into two main categories in terms of mechanism - mechanical and electropneumatic.
Mechanically operated paintball markers operate using solely mechanical means, and as such do not use electro-pneumatic solenoids controlled by an electronic board to fire.
There five main methods of mechanical operation:
Pump or Bolt Action: the mechanism of the marker must be manually reset in between each shot, similar to pump action shotguns and bolt action rifles. Markers of this type are the oldest used in the sport as the first ever game of paintball was played using the bolt-action Nelspot pistol. There are two main patterns of internals upon which most pump and bolt action markers operate:
Double Action: the trigger mechanism of the marker both fires and resets the firing mechanism, similar to the way a double-action revolver operates. Examples include the Line SI Advantage, the NSG Splatmaster Rapide and the Brass Eagle Barracuda.
Throwback Semi-Auto: The mechanism of the marker is cycled using gasses released by the valve which reset the firing mechanism between each shot, similar to the way some semi-automatic rifles such as the AK-47 operates. The internals of blow-back operated markers can be either inline, with the bolt, valve and hammer all aligned along the same axis such as the Tippman 98, or stacked tube with the bolt in a separate tube from the hammer and valve such as the King-man Spider.
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