Paintball Equipment - Markers

Markers

A paintball marker is the primary piece of equipment used in paintball to tag an opposing player. An expanding gas (usually carbon dioxide or high-pressure air) forces a paintball through the barrel at a muzzle velocity of approximately 300 ft/s (91 m/s). This velocity is sufficient for most paintballs to break upon impact at a distance, but not so fast as to cause tissue damage beyond mild bruising. Nearly every commercial field has, and strictly enforces, a rule limiting the muzzle velocity of a paintball at or below 300 ft/s (91 m/s). Speeds above 250 are typically needed to ensure the paintball breaks on impact; the field limit is thus usually somewhere in between, often 260-280fps. The technology used to design and build paintball markers has advanced over time, beginning with the original "Nel-Spot" bolt-action pistols, progressing to pump-action markers, then to semi-automatic mechanical markers, and finally culminating in the electropneumatic paintball marker.

In mechanical designs, the trigger manipulates a sear, which is holding a hammer, ram, or sealed gas chamber in its resting state. Pulling the trigger releases the sear, allowing the marker's action to cycle. There are a variety of mechanical designs, the most common being the "blow-back" marker, which utilizes a spring-loaded ram released by the sear to open a pin valve; the pressurized gas released through the valve is directed through the bolt to fire the marker, and also pushes the ram back where it is caught again by the sear, resetting the action for the next shot. There are other systems that saw success in earlier days of the sport, such as blow-forward (AGD Automag) and pneumatically actuated recocking (WorrGames Autococker); elements of these designs were carried forward into modern electropneumatic designs but the original examples of these mechanisms are rarely seen today.

In electropneumatic designs, the trigger, instead of being mechanically linked to the action of the marker, simply activates an electronic microswitch (or more recently, a magnetic or optical sensor). That information is passed through control circuitry to a computer-controlled solenoid valve which can open and close very quickly and precisely, allowing gas to move into or out of various pressure chambers in the marker to move the bolt and fire the paintball. This disconnect of the trigger from the action allows electronic trigger pulls to be very short in length and very lightweight (similar to a mouse click; the mechanisms are virtually identical), which dramatically increases rate-of-fire over a fully mechanical design. Solenoid-controlled gas valve designs also allow for reduced weight of internal parts, which both lightens overall weight and reduces the time it takes for the marker to cycle through firing a single paintball.

In fully electropneumatic designs, there are two primary mechanism types:

• The "poppet valve" (or simply "poppet") design functions similarly to a mechanical blowback or Autococker-style marker; when the trigger is pulled, low-pressure air from the solenoid brings the bolt forward to chamber the paintball and also sends a connected, weighted ram into a pin valve, which opens to allow high-pressure air into the chamber, launching the ball. Then, either additional air from the solenoid in a "two-way" design, or a spring in a "FASOR" (Forward Air, Spring-Operated Return) design, returns the bolt and ram to the open position. Another paintball drops into the open chamber and the action is ready to fire again. Poppets are typically valued for high gas efficiency, as the low-pressure system to move the ram and the limited time the high-pressure valve is open saves gas compared to most competing designs. However, the nature of the mechanism produces very loud "pops" when the marker is fired, and the movement of the ram and bolt and the sudden high-pressure release of air can increase recoil, affecting accuracy during rapid fire. They are also more mechanically complex; most designs require two regulators, one to adjust the "high-pressure" air launching the ball, and a second one to further lower the pressure to operate the ram.
• The "spool valve" ("spoolie") typically uses the bolt itself to hold air in a filling chamber. This high-pressure air is either self-balancing so there is no net force to open the bolt (a "balanced" spool valve), or is kept in check by additional air from the solenoid pushing backward on the bolt (an "unbalanced" or "dump-valve" spool). When the trigger is pulled, the solenoid of a balanced system pushes the bolt forward, or in a dump-valve vents the air from the forward pressure chamber. As the bolt moves forward, it seals off the inlet allowing high-pressure gas into the filling chamber, and then releases the stored charge of air through the bolt into the main chamber to launch the ball. The solenoid then resets the bolt by allowing air to re-enter the forward chamber and pushing the bolt backwards to re-seal the filling chamber and open the inlet. Spool valves are typically valued for their quieter and smoother operation, and their reduced mechanical complexity (often the only major moving part is the bolt), but are often less gas-efficient than poppet valves due to the large charge of air behind the bolt and the single operating pressure used both to move the bolt and launch the ball.

In addition to fully electropneumatic marker designs, electronic trigger frames, with a solenoid-controlled sear, can be fit to most mechanical "blow-back" designs, such as the Kingman Spyder line of entry-level markers. These allow the high rates of fire seen in full electropneumatic designs at a very low cost compared to higher-level markers; however they typically have both the higher recoil of poppets (even worse, typically, as the designs use a traditional high-mass hammer driven forward by a spring) and relatively low gas efficiency due to a single operating pressure.

Contrasting this move toward high rates of fire, there is also a strong following of stock-class paintball games, where players use older, purely mechanical pump-action marker designs to purposefully limit rate of fire. Pump markers require the player to recock the marker, using a pump handle similar to a pump-action shotgun, before each shot. Stock-class games and competitions require the use of pump markers, and also often limit the types and capacities of propellant sources and loading mechanisms that players may use. With the decreased rate of fire and carrying capacity, increased need for reloads of both paintballs and propellant, and the generally quieter report of these markers, stock-class play places more emphasis on accuracy, stealth, and tactics.