Paintball marker

A paintball marker, also known as a paintball gun, is the central or main piece of equipment in the sport of paintball. Markers make use of an expanding gas such as carbon dioxide, compressed air or nitrogen dioxide to propel paintballs through the barrel. The paintball community generally prefers to use the term "marker" rather than "gun" in order to mitigate the public perception that paintball markers are weapons, and that paintball is a dangerous sport. The term derives from its original use as a means for forestry personnel and ranchers to mark trees and wandering cattle.

The muzzle velocity of paintball markers can approach 300 feet per second (91 meters per second, or about 201 mph). Muzzle velocity above 300 feet per second (fps) is ruled unsafe in most commercial paintball fieldsFact|date=November 2007. Below 300 fps, most paintballs will break upon impact without leaving significant damage beyond a small bruising. Due to the speed of flying paintballs, players must wear masks to protect the eyes, mouth, and ears when barrel blocking devices are not in place.

The majority of paintball markers have four main components: "body", a "hopper", a "gas system (air tank)", and a "barrel". There is, however, a strong following of "stock-class" players who use markers with an intentionally low rate of fire and capacity. Stock-class markers are usually pump-action and powered by 12-gram CO₂ powerlets.

Marker body

The marker body is where most of the marker's functional and aesthetic features are contained. Most marker bodies are constructed from aluminum to reduce the marker's weight, and feature custom milling and color anodizing. In terms of function, the body contains the main components of the firing mechanism: the trigger frame, bolt, and valve.

External design

The largest external and ergonomic difference in marker bodies is trigger and barrel position. High-end marker designers work to push the trigger frame forward toward the center, or slightly forward of center of the body on speedball-oriented markers. This allows the HPA tank to be mounted in a position that provides compactness and balance without requiring any additional modifications that drop the tank down and forward. (Such aftermarket "drop forwards," may create a larger gun profile, which can result in eliminations due to hopper hits.) In economy markers, users often modify the marker to produce the same feel, albeit by sacrificing a low profile. Though this is an irrelevant consideration in games where equipment hits do not count, a majority of fields, including those focused on woodsball games, count hopper hits as an elimination. However, some markers mount the barrel farther back in the gun body to preserve overall compactness in lieu of positioning the trigger forward on the marker body.

Trigger frame

Triggers are one of the most important functional features, as they are the the player's primary means of interaction with the marker. The amount of force required to fire the marker, as well as the distance the trigger travels before actuating (the "throw") has a major effect on the player's ability to achieve high rates of fire. Higher-end markers employ electronic trigger frames with a variety of sensing methods (microswitches, hall effect sensors, or break-beam infra-red switches). These triggers feature very short throws, which allows for higher rates of fire. Non-electronic markers may alternatively use carefully set pneumatics to achieve a light and short trigger pull.

The trigger frame on non-electronic mechanical markers simply use a series of springs and levers to drop a sear, which allows the hammer in the body to propel forward. On electronic markers, the trigger frame houses the electronics that control the solenoid, as well as other features on the marker such as ball detection systems. Upgraded circuit boards are available to improve various features in the marker.

Bolt and valve assembly

The bolt and valve assembly is the core of any marker. Together, they provide the mechanism by which the marker fires. The valve is the mechanical "switch" that controls whether the marker is firing or at rest, while the bolt directs the flow of air and controls the entry of paintballs into the chamber. The bolt and valve may be separate components (as is the case in many blowback and poppet-based electropneumatic markers), or the valve may be "built into" the bolt (as is the case in spool-valve electropneumatic markers).

The majority of markers on the market today are open bolt, which means that when the marker is at rest, the bolt is in the "back" position, and the firing chamber is exposed to the stack of paintballs being fed by the loader. Some markers, however, are closed bolt, meaning that in the rest position, the bolt (and paintball to be fired) are forward, and the feed stack is shut off from the chamber. It was once believed that closed bolt markers were more accurate due to the absence of a reciprocating mass when the marker was fired, but tests have shown that the position of the bolt has little effect on a marker’s accuracy. [ cite news|url= http://www.warpig.com/paintball/technical/paintguns/balistic/closedopen.shtml |title=Where’s the Bolt? |accessdate=2007-12-14 |work= ]

Bolt and valve in mechanical markers

The majority of mechanical markers employ a simple blowback design utilizing a poppet valve (also known as a “pin valve”), which is opened when struck by a compression force, provided in the form of a hammer propelled by a spring. These sorts of markers generally use a “stacked tube” design, in which the valve and hammer is contained in the lower tube, while the bolt, which is connected to the hammer, is in the upper tube (Some manufacturers, however, such as Tippmann, have managed to incorporate the valve, hammer, and bolt into a single tube, as exemplified in the Tippmann 98 Custom). The hammer is held in the back position, with the spring compressed, by a sear. When the trigger is pulled, the hammer is propelled forward by the spring, into the valve. The air released by the valve is then simultaneously channeled up to the bolt to fire the paintball, and back to push the hammer back into the cocked position (hence the name “blowback”).

Poppet valves are usually easy to replace and require little, if any, maintenance. The downside to this design, however, is its high operating pressure, which leads to a larger recoil and arguably less accuracy. Some markers, such as the Autococker, have a separate firing and recocking sequence, which decreases the recoil caused by the cycling of the hammer. Any marker with a hammer, however, has a significant firing delay when compared to a full electropneumatic.

Some markers are a hybrid of mechanical and electronic features. In these markers, the hammer and spring continues to activate the valve, but the hammer is released by a solenoid in an electronic trigger frame.

Bolt and valve in electropneumatic markers

Whereas mechanical markers use a spring and hammer to actuate the valve and cycle the bolt assembly, electropneumatic markers rely entirely on the rerouting of air to different locations in the marker. This rerouting is controlled by an electronic solenoid activated by the trigger. There are two broad categories of bolt/valve mechanisms within electropneumatic markers: poppet-valve-based and spool-valve-based.

"Poppet-valve-based" electropneumatic markers are very similar to mechanical blowback markers in that they feature a stacked-tube construction, built around a poppet valve, that is opened when struck by a force. However, unlike mechanical markers which provide that force with a hammer propelled by a spring, the valve in poppet-valve electropneumatic markers are activated by a pneumatic ram. In the same way that the bolt is connected to the hammer in mechanical blowbacks, the bolt in poppet-based electropneumatics is connected to the ram. Poppet-valve electropneumatics share the same disadvantages as their mechanical counterparts, namely external moving parts, a reciprocating mass, and a louder firing signature. However, they are also more gas efficient than spool-valve electropneumatics since the poppet valve only releases the precise amount of air needed to fire the marker. Examples of markers that utilize this mechanism are the WDP Angel, Planet Eclipse Ego, Bob Long Intimidator, and Bushmaster. [ [http://www.zdspb.com/tech/misc/markers_hammer.html Maker Classification - Markers Using a Hammer] , at ZDSPB.com]

In a "Spool-valve-based" electropneumatic marker, the bolt also acts as the valve. This eliminates the need for a stacked tube construction, and indeed spool valve markers are notable for their compact profile. Rather than employ a cycling hammer or ram that strikes a pin valve, the movement of the bolt is controlled entirely by the routing of air into small chambers in front of or behind the bolt. Additionally, there is an air reservoir behind the bolt that contains the air that will be used to fire the paintball. When the marker is at rest, air is routed to the front of the bolt to prevent any of the air in the reservoir from escaping. When the trigger is pulled, that air is either vented, allowing the air in the reservoir behind the bolt to simply push it forward (as is the case in an “imbalanced spool valve” design), or the air is rerouted to a small chamber behind the bolt (separate from the reservoir), which then pushes the bolt forward (a “balanced spool valve” design). In either case, the movement of the bolt forward exposes pathways in the bolt or the marker that allow the air in the reservoir behind the bolt to surge forward and fire the paintball.

A typical spool valve has at least one O-ring that undergoes a shear/compression duty cycle every shot, leading to faster wear and less reliability. Additionally, the necessity of an air reservoir makes them less gas efficient than their poppet-valve counterparts. However, since spool-valve markers feature no reciprocating mass (other than the bolt) and require little pressure to operate, they have less recoil and very little noise. Examples of markers that utilize this mechanism are the Dye Matrix, Smart Parts Shocker, and Smart Parts Ion. [ [http://www.zdspb.com/tech/misc/markers_nohammer.html Marker Classification - Marker Without a Hammer] , at ZDSPB.com]

Tuning the bolt and valve system

In mechanical and poppet-based electropneumatic markers, the valve is usually designed with a specific operating pressure in mind. Low pressure valves provide quieter operation, and increased gas efficiency when tuned properly. However, excessively low pressure can decrease gas efficiency as dramatically as excessively high pressure.

Additionally, the valve must be set such that it releases enough air to fire the paintball. A valve that is not tuned properly can cause an insufficient amount of air to reach the bolt. This phenomenon, known as “shoot-down,” causes fired paintballs to gradually lose range, and can also occur at high rates of fire. Some markers have integral or external chambers, called low-pressure chambers, which hold a large volume of gas behind the valve as a means of solving shoot-down.

Due to the open bolt design of most markers, the bolt movement when a marker is fired can cause some air to blow up the feed tube and disrupt the feeding of paintballs into the marker. Proper tuning and choice of loader can solve this, however.

Loaders

Loaders, also commonly known as "hoppers", hold paintballs for the marker to fire. There are many variations, but the primary types are gravity feed, agitating, and force-feed. Stick feeds are also a means to hold paintballs, though they are not, strictly speaking, considered "hoppers".

While agitating and force-feed hoppers facilitate a higher rate of fire, they can fail due to dead batteries as well as contact with moisture, which keeps many woodsball and scenario players away from them. Ball breaks pose a problem for all hoppers, regardless of design. When a paintball leaks paint into the hopper from a break in the hopper, it can cause the gelatin shells of the paintballs to deteriorate and sometimes stick together.

tick feed

"Stick feeds" are primarily used on pump and stock-class markers. They consist of simple tubes that hold ten to twenty paintballs. Stick feeds are usually parallel to the barrel and the player must tip (or "rock", leading to the term "rock n'cock") the marker to load the next paintball. Some stick feeds are vertical, or at an incline to facilitate gravity feeding, though this contravenes accepted stock-class guidelines.

Gravity feed

"Gravity feed" is the simplest and cheapest form of hopper available. Gravity feed hoppers consist of a large container and a feed tube molded into the bottom. Paintballs roll down the sloped sides, through the tube, and into the marker. These hoppers are limited to feeding 8 balls per second reliably. Gravity feed hoppers are very cheap, since they are made of only a shell and a lid, but can become jammed easily as paintballs pile up above the tube. Occasionally, rocking the marker and hopper can keep the paintballs from jamming at the feed neck.

This problem is made worse when using a modern fully-electronic marker. Most economic and mechanical markers use a blowback system for recocking, or other methods where a large reciprocating mass is involved. This will shake the balls in the hopper slightly, facilitating gravity feed. A marker with both electronically controlled recocking and firing will often exhibit no shake whatsoever while operating. Because of this, small packs in the hopper are not broken up, and feeding problems are made worse.

Agitating

"Agitating hoppers" use a propeller spinning inside the container to agitate, or stir up, the paintballs. This prevents them from jamming at the feed neck and feeding more rapidly than equivalent gravity feeds. Older tournament-level hoppers are of the agitating type, since the higher rate of fire requires a more advanced and consistently-loading hopper.

Unlike the previous types of hoppers, there are two types of Agitating Hoppers: those with "eyes" and those without. These eyes consist of a LED (light emitting diode), and a photodetector (typically a phototransistor or photodiode, which is sensitive to light) inside the neck (tube) of the hopper and are often inside electronic markers. Eyes are used to detect whether a ball is present or not. In a marker, the eyes will keep the gun from shooting until a ball is fully loaded into the chamber. In a Hopper the eyes detect when a ball is not present to cause it to turn. Agitating hoppers without eyes will run down batteries and may bend or dent paintballs which will in turn cause a short, less air efficient, skew shot. Agitating hoppers with eyes will only spin whenever there is not a ball, which causes less chance of damage and longer battery life.

One notable hopper is the Tippmann Cyclone Feed system. It could be called a hybrid agitator/force feeder, because it contains both in the form of a five point star shaped piece that captures five balls and forces them into the chamber when the bolt is open. It is used on the Tippmann A5, X7, and can be installed on the 98 Custom. The Cyclone system uses excess gas tapped from the power tube to force feed a ball into the gun. There are several benefits to this, it does not require batteries, is not affected by water, and it only cycles when the gun fires. Contrary to popular belief, the Cyclone does not require more CO2/HPA, the gas used to drive it would just be released into the body of the marker if it were not used. Its ratchet does wear out over time, however, and to combat this there are after market aluminum parts available.

Force-feed

"Force-feed hoppers" utilize an impeller to capture paintballs and force them into the marker. The impeller is either spring-loaded or powered by a belt system, allowing it to maintain constant pressure on the stack of paintballs in the feed tube. This allows force-feed hoppers to feed paintballs at high speed (over 22 balls per second), since the mechanism does not rely on gravity to move paintballs into the feed neck. Force-feed hoppers are the dominant form of hopper in tournament play, as they are the only loader capable of keeping up with the high rate of fire found in electropneumatic markers.

Some markers, such as those manufactured by Real Action Paintball, use force-fed loaders shaped as firearms magazines. These are preferred when a low profile is required, as in woodsball 'sniper' positions. Even more unusual are fully-contained magazines, incorporating both a source of propellant gas and force-fed paintballs such as those used in the markers manufactured by Tiberius Arms.

The newest type of force feed hoppers communicate wirelessly with the marker's electronics via radio frequency. This allows the hopper to begin feeding paintballs before the pneumatic system of the marker has even begun cycling the next shot. Not only does this system almost totally eliminate mis-feeds, but it can greatly increase the speed of the loader and increase battery life due to the loader only being in operation when the marker is preparing to fire, as opposed to the continuous operation of many other loaders. An example of the radio frequency activated hopper is the DXS/Draxxus Pulse. It should be noted, though, that Procaps (the maker of the Pulse) is being sued by NPS (maker of the Halo B, another force-fed hopper) for alleged intellectual property theft of the magnetic aspect of the RF Chip and the internals of the Halo hopper. DXS/Draxxus has halted production of the Pulse, and its future production is unclear. Furthermore, use of this feature requires that a chip be soldered to the electronics board inside the marker. Many new marker manufacturers and aftermarket electronics companies have announced that their markers/boards will support this new technology.

Propellant system

The tank holds a compressed gas used to propel the paintballs through the marker barrel. The tank is usually filled with CO₂ or compressed air. High Pressure Air (HPA) is sometimes referred to as "nitrogen", as air is 78% nitrogen, or because these systems can be filled with industrial nitrogen. Due to the instabilities of CO₂, HPA tanks are desired for consistent velocity. More exotic means of paintball propulsion include the combustion of small quantities of propane or electromechanically operated spring-plunger combinations similar to that used in an airsoft gun.

CO₂

Carbon dioxide, or CO₂, is a common propellant used in paintball, especially in cheaper guns. It typically comes in the form of a 12 gram powerlet, mainly used in stock paintball and in paintball pistols, or a tank. The capacity of a CO₂ tank is measured in ounces of liquid it can store. A CO₂ tank is usually pressurized at around 1800 PSI. At this pressure, CO₂ tends to form a liquid. When it is released, only a portion of the CO₂ is stored as gas, and the rest (liquid CO₂ in the tank) must first vaporize into a gas before it can be used. This process leads to some commonly-known problems such as inconsistent velocity. It especially has problems in cold weather, which slows vaporization and increases the chance for liquid CO₂ to be drawn into the marker. Liquid CO₂ injected into the marker is very cold, and can damage some of the internal mechanisms. Anti-siphon tanks have a tube installed inside the cylinder which is bent to prevent liquid CO₂ from being drawn in. They must be screwed in so that the tube faces upwards to function properly.

High Pressure Air

High Pressure Air (HPA) or compressed air or nitrogen is stored in the tank as a gas, bypassing the evaporating issue. Air is stored in the tank at a very high pressure, typically 3000-5000 psi, and output is controlled with an attached regulator, this regulates the pressure from 250 psi to around 850 psi (the output pressure of CO2) depending on the type of tank. This results in a much more consistent velocity than with CO₂. HPA tanks have two measurements: PSI and in³.

HPA tanks are more expensive, since they must be rated for a much higher pressure, and are typically made from more expensive materials. Tanks can be purchased that are steel or aluminum, or wrapped carbon fiber bottles. Carbon fiber bottles are much more expensive ($200+ USD) because of the price of materials and manufacturing.

Gas regulation

Marker systems have a variety of regulator configurations, ranging from completely unregulated, to some high end systems using four regulators, some with multiple stages.

The regulator system affects both the accuracy and at what velocity the marker operates(in conjunction with valve dwell/hammer pressure). CO₂ regulators have an additional job of making sure no liquid CO2 enters the marker and expands, which causes a dangerous velocity spike. As such, regulators for use with CO2 often sacrifice throughput and accuracy to ensure the marker operates in a safe manner. HPA-only regulators tend to have an extremely high throughput and have design considerations to ensure uniform pressure between shots for marker accuracy at high rates of fire. Tournament markers usually are equipped with four regulators, each with a specific job. The tank regulator first moves the 3000psi to 4500 psi HPA (in CO₂, this is not present) down to a more predictable pressure, usually between 600-800 psi. A second regulator is then employed, which regulates this pressure to one close to the firing pressure, and is a matter of personal preference between players. A pressure closer to the final allows for greater consistency, but a larger difference reduces shoot down. The air is then supplied to a regulator on the marker body, where the final output pressure is decided. This can be 800 psi for entirely unregulated CO2 markers, to 150-200psi for extremely low pressure markers. Some markers have great success in a low-pressure conversion, while others do not. After the firing pressure is decided, tournament-oriented markers will use one more regulator to supply gas to a separate pneumatic system for any other functions, such as bolt movement. This is an extremely low volume, extremely low pressure regulator, usually under 100 psi.

Barrels

A barrel serves to direct the paintball and control the release of the gas pocket behind it. Several different bore sizes are available, to best fit different sizes of paintball, and there are many different lengths and styles. Most modern paintball markers have barrels that screw into the front receiver, as opposed to some older types which slide a barrel on and screw it in place. Barrel threading must be matched to that of the marker. Common threads are Angel, Autococker, Impulse/Ion, Shocker, Spyder, A-5, and 98 Custom.

Barrels are manufactured in three basic configurations: one piece, two piece, and three piece. It is more common to refer to a barrel with interchangeable bores, be it two or three piece, as a "barrel system," rather than a two-piece or three-piece barrel. This avoids confusion, as many two-piece barrel systems do not use an interchangeable bore system.

One piece barrels are machined from a single piece of material, usually aluminum. Paintballs can range from .669 to .695 caliber, and barrels are honed to match these diameters. Many one piece barrels have a "stepped bore" that increases from their rated bore size to around .70 caliber after eight inches.

Two piece barrels consist of a "front" and "back". The back attaches to the marker and is machined with a pre-specified bore between .682 and .695 caliber. The front makes up the rest of the length of the barrel and contains the porting. Fronts usually have a larger bore than the back.

Three-piece barrels, instead of having multiple backs each with a different bore, have only a single back. A series of inserts, or "sleeves", with differing bores are inserted into the back. The front is then screwed on to keep the sleeve in place. Sleeves are generally offered in either aluminum or stainless steel. This type offers the most flexibility in that the user needs only one set of sleeves and a back for each marker they own. They can also select front sections to make the barrel length they prefer. This type also generally offers the widest selection of barrel diameters, usually .680, .681, .682, .683, and so on up to .696 caliber. The sleeves are generally manufactured in stainless steel or aluminum. Aluminum inserts are generally known to dent or scratch easily, so stainless steel inserts are usually suggested.

A good example is the Smart Parts Freak barrel, which was the first product to innovate this idea. While sacrificing effective barrel length, this system allows for many bore sizes, allowing exceptional accuracy.

Length

The length of barrels can range between 3 and 21 inches, though some custom barrels exist which may reach up to 48 inches. Recent tests have suggested that neither accuracy nor efficiency can be gained in barrels beyond 8 inches long, as a paintball needs an unported 6 to 8 inches to stabilize and achieve maximum gas efficiency. Longer barrels generally make less noise than shorter barrels by allowing excess gas to escape more slowly from porting along the sides. Longer barrels can allow players to "sight in" faster than they would with shorter barrels and thus give the perception that longer barrels are more accurate. The barrel choice commonly used by players is 14-16", as it keeps the balls shooting straight, but the marker is still light and maneuverable. Many players will also choose the longer barrels as it allows them to push aside the large inflatable bunkers commonly used in paintball tournaments while still staying behind cover.

Most barrels are "ported" (or "vented"), which means that holes are drilled into the front of the barrel allowing the propellant to dissipate slowly, decreasing the sound signature of the marker. There has been a considerable amount of marketing hype surrounding barrel porting, but there appears to be [http://www.automags.org/forums/showthread.php?t=126924 no basis] for claims of the benefits of porting (such as that it decreases "turbulence", increasing accuracy), other than the decrease in sound signature.

It should be noted that porting in the first eight inches of the barrel length decreases a marker's gas efficiency. For example, if a 16 inch barrel has large porting that starts six inches past the threads then it has an effective barrel length of only six inches. At that point, the ball has to travel the other 10 inches on its own momentum. The friction within the barrel must be overcome with a larger burst of gas, decreasing efficiency. Porting in a barrel before the paintball has completely stabilized can also dramatically increase noise, as the gas still has a significant amount of pressure built up.

Bore

The bore is the interior diameter of the barrel. The bore properly matching the brand of paint being fired is the most critical aspect of a barrel, far beyond gas efficiency or silence in most situations. A poor bore/paint match will result in velocity variations, which causes inaccuracy. Two and three-piece barrels allow the barrel bore to be matched to the paint diameter without entirely new barrels. Paint to barrel matching is doubly important in closed-bolt markers (as ball detents in such markers serve to prevent double-feeding, not to prevent roll-outs) such as Autocockers, because small paint in a large barrel can roll out the front of barrel.

pin barrels

The Flatline barrel, manufactured by Tippmann is designed to decrease the parabolic travel of fired paint. The barrel is curved such that an accelerating paintball contacts the top of the barrel, imparting backspin. This backspin generates lift (known as the "Magnus Effect"), resulting in a flatter arc and longer range. This is especially beneficial in woodsball or scenario paintball where overhanging branches limit the range of traditional barrels. It is available for the Tippmann Model 98, 98 Custom, A-5, and X7. There are conversion kits to allow the use of the flatline barrels on some other guns, as well.

The Apex barrel, manufactured by Ben Tippmann Paintball Design, also imparts spin to the ball. Unlike the flatline barrel, the Apex can impart back, top, or sidespin (this allows balls to arc around some obstacles, or have them drop over bunkers). The magnitude of spin can also be varied, allowing for a gentle curve or a sudden hook. It is available with threads for most markers. There are many ways to fit an Apex tip onto a regular barrel, ranging from improvised methods such as electrical tape, to sleeves that go over the tip of the barrel, sold at Underground Mod Shop and Palmer's Pursuit Shop.

Both the Flatline and Apex barrel systems have been criticized as sacrificing force and accuracy for increased long range. Paintballs fired from these barrels are able to travel farther, but due to the backspin and consequent lower speed, the chance of the paintball breaking or even hitting its target at the increased range is diminished appreciably. Given that players are tempted to utilize the extra range of the barrel at distances where the paint will not break, the barrels' effectiveness as an elimination tool (as opposed to psychological and area denial effect tools) is questionable.

Firing and trigger modes

Since the advent of semi-automatic markers in the early 1990s, both insurance and competitive rules have specified (at most fields) that markers used in paintball must be semi-auto only; specifically, that only one paintball may be fired per trigger pull. While this was a perfectly clear definition when markers were all based on mechanical/pneumatic designs, the introduction of electronically controlled markers in the late 1990s brought technology beyond the rule. Electronic markers are often controlled by a programmable microcontroller, on which any software might be installed, including software that may add more than one shot per trigger pull in various ways. This effect is generally referred to as "shot ramping" (as opposed to velocity ramping): an electronic firing mode where a consistent full-automatic rate-of-fire will be triggered as long as the player maintains a certain, lower trigger-pulls-per-second.

Pump action

Pump action markers must be manually re-cocked after every shot, much like a pump action shotgun. This manual action is much slower than other configurations, but is preferred by some over styles of markers as a challenge to themselves to learn how to play with less rate of fire. Others merely cite the increased satisfaction of playing with a pump. The slower pace of play also forces pump players to make every shot count, leading many to believe that the markers themselves are more accurate, which may or may not be true. However, when properly modified, high end pump markers have been known to achieve extremely consistent velocities when chronographed.

Stock class paintball exclusively utilizes a certain type of pump marker known as a stock class marker. This is a pump marker with a specialized stock class feed system- see stock paintball.

Semi-automatic

Semi-automatic markers use a variety of designs to automatically cycle a bolt and load a new paintball into the chamber with each trigger pull. This frees the player from manually pumping the marker, allowing them to increase their rate-of-fire. Semi-auto can both be used with a mechanical trigger or with electric trigger frames. The major benefits of an electric trigger frame is a lighter trigger pull as well as less space between the trigger and the pressure point (allowing the player to tap the trigger faster and shoot at higher rates of fire.) Semi automatic is the regulated mode of fire for NPPL.

Fully-automatic

Fully-automatic markers fire continually for as long as the trigger is held down. The Tippmann SMG 60 was the first fully-automatic paintball marker. Most electropneumatic paintball guns feature this mode, but the full-auto feature can be added to any electropneumatic marker by installing an aftermarket logic board, or buying a completely new electronic trigger frame.

Also, similar to the full-auto mode, some markers come equipped with burst modes. Ranging from three to six to nine shot burst, these modes can allow the player to take accurate shots with a quick pull of the trigger, loosing more than one ball to increase their chances of a hit. Also, when shooting quickly in burst mode, the rate of fire can become equal to that of the fully automatic mode, useful in close range situations.

Ramping

Ramping is a feature in some electronic guns that automatically shifts the mode of fire from semi-automatic to fully automatic as long as the trigger is pulled at a specified rate. Ramping can be difficult to detect, both because it may not be consistent or easily observable by a human. Ramping modes can also be hidden in the software, such that a marker will fire in legal semi-auto mode when being tested, but in an illegal ramping mode by the player.

To counter the problems with enforcing semi-auto rules, some leagues allow a specific ramping mode. The rule specifies a minimum time between shots of 66 milliseconds (approx. 15 shots per second), and that no more than one shot may be fired for the first three trigger pulls. The rate of fire is enforced using a device called a PACT Timer, a standard firearms timing device that measures the time between shots. The following are common league specific ramping modes. Many high-end markers have these modes preset in their firmware:
*PSP Ramping - Ramping kicks in after 3 shots; player must maintain 5 bps to remain ramping. Rate of fire cannot exceed 13.33 bps.
*NXL Ramping - Ramping kicks in after 3 shots; player needs only to hold down the trigger to maintain fully automatic fire. Rate of fire cannot exceed 13.33 bps.
*Millennium Ramping - Ramping kicks in after 6 bps; player must maintain 6 bps to maintain fully automatic fire. Rate of fire cannot exceed 12 bps. (This is true in some but not all markers.)

Use by law enforcement

Paintball markers have been used by law enforcement as antiriot weapons, in two modes:
*Loaded with pepper-spray projectiles: see Pepper Ball rounds.
*Loaded with paint projectiles to try to mark particular rioters so that police can easily identify and arrest them later.
*The mechanism of the Automag make of paintball marker was used in the FN 303 antiriot gun.

References

See also

* Paintball pistol
* Stock paintball

External links

* [http://www.zdspb.com/tech/index.html ZDS Paintball] Detailed descriptions and animations of paintball marker mechanics
* [http://knol.google.com/k/steve-mccarty/top-paintball-guns-in-every-price-range/2numhlc3ztqtb/2?locale=en# Paintball Marker Information]