In the years since the game began, paintball equipment has evolved relatively rapidly. What started as manually cocked, single-shot, hand-held pistols with an ammo capacity of 10 balls, have evolved into pneumatically cocked, electronically-controlled, programmable-shot guns with an ammo capacity of over 200 balls.

Early paintball guns were designed and manufactured by BB and pellet gun companies for the Forestry Service to use in  marking trees. Performance and efficiency were not issues.  The designs for the early guns were nearly identical in function with the BB or pellet gun, with the exception of a larger bore for the paintball. While BBs are basically .177 caliber (177 thousandths of an inch in diameter), normal paintballs are .68 caliber (68 hundredths of an inch). The larger size of the paintball and the origins of the design contributed to an inefficient use of CO2. This was not an issue as long as your targets were stationary trees. When someone discovered that it was fun to shoot other people with these guns, performance suddenly became quite important. Even the smallest gains in performance would become a perceived advantage over your opponent.
The original paintball gun, the Nelspot 007, was developed for the forestry industry as a method of marking trees from a distance. It was developed by Daisy, a company well known for its air-powered BB and pellet guns. Like a bolt-action rifle, cocking action was manual via a lever on the side of the gun. The balls were loaded from a tube running parallel to and above the bore, which means the gun had to be tilted to allow balls to roll in every time it was cocked.  The power source for the gun was a 12 gram Co2 cartridge, commonly used in BB and pellet guns. As with Daisy’s other air guns, the Co2 cartridge was stored inside the grip frame and accessed through a removable grip panel. A stock 007 would get around 20 shots before the cartridge had to be changed.

Like the Nelspot, the PG (later PGP), distributed by Pursuit Marketing Incorporated (PMI), was designed from available air gun technology. The guns were manufactured by Benjamin/Sheridan, and used some of the same parts as that company’s popular BB/pellet guns.  The earliest version of the gun had a manual cocking knob on the rear. Like the Nelspot, it was powered by a single 12 gram Co2 cartridge, and had a magazine running parallel to the bore, which necessitated tilting the gun to load each shot. The Co2 cartridge is stored horizontally in the front of the bottom tube.

Another single shot pistol to enter the market was the NSG Splatmaster. The Splatmaster was purposefully designed for playing the game of paintball, and marketed through a franchise program for what was called “The Survival Game”. Although many people had their first paintball experience with a Splatmaster in hand, the gun did not spawn the same lineage as the 007 or PGP. There were some upgrades for the Splatmaster, but the plastic one piece body design limited the easy attachment of bolt-on parts. While many guns based directly on the 007 and PGP are still in production today, the Splatmaster and its design eventually became extinct.

It wasn’t long before players began seeking performance increases in order to get a competitive edge on their opponents. The vast majority of the modifications focused on increasing the rate of fire, although some were aimed at improving accuracy, and others, like the “field strip notches” cut into early guns were for convenience. The “notches” made disassembly faster and easier.  A lot of the modifications were what was known as “garage modifications”, since they were invented by players and basically done in their homes. Some of these “garage modifications” eventually lead to people forming their own businesses, many of which are major players in today’s paintball industry.

Unfortunately, accuracy, and range rely heavily on the most inconsistent element in the mix – paintballs. According to one paintball legend, the standard caliber of the paintball came about because that just happened to be the size of the available encapsulating machines of the time, which were used for making pills for horses. Being nearly seven tenths of an inch in diameter, the average paintball holds quite a bit of paint. The fact that the fill is fluid, the shell is somewhat soft and flexible, and there is a seam running the circumference, all contribute to inconsistencies in accuracy. Range is determined by the speed at which the paintball is launched, and the maximum accepted legal speed was determined by the impact strength of the ball, which is a direct result of its size. For instance, at one time there was a push for .62 caliber balls by some manufacturers, and fields generally allowed higher velocities for those because of a perceived lesser impact force.

Paintball quality has improved over the years, but it still remains the weakest link in the chain. Despite that weakness, there was plenty of room for improvement in the accuracy of early paintball guns. Following traditional firearms theories, lengthening the barrels of the guns were among the first modifications toward this goal. Barrel extensions were available for both the 007 and PGP, and as later discussed, replacement bodies with longer barrels. Another common procedure was to polish and hone the interior of the barrel to a fine finish. On both the 007 and PGP, care had to be taken to maintain the inside of the barrel. The brass of the PGP would eventually, over time, tarnish, while the steel of the 007 would rust quite quickly if not cleaned.

Obvious early enhancements aimed at increasing rate of fire included polishing internal parts and changing spring rates for easier pumping action. One modification towards higher rates of fire (and comfort) was to attach pump handles to the guns, which would allow them to be cocked with an action similar to a pump shotgun. The idea caught on and aftermarket pump handles were sold for the 007, while the original PG had one added on the production line to become the PGP.

Another rate of fire enhancement involved adding capacity and the effect of gravity to the ammunition magazine. Add-on products involved the simple attachment of a vertical tube to the rear of the standard magazine. Gravity would then cause the balls to feed at a quicker rate, since tilting the gun for each pump stroke was no longer necessary. The only flaw in this system is that gravity no longer had an impact after the magazine got below the level of the vertical part of the tube. To remedy this, the next level of modification involved removing the horizontal feed tube and replacing it with what is called a “direct feed” or “gravity feed” nipple. This was a common modification on both Nelson and Sheridan guns, and usually involved soldering a brass nipple onto the gun, although other methods of attachment were also used. These modifications were either done in the home, or by custom machine shops.

Rate of fire was also increased with the addition of an auto-trigger. With an auto-trigger, the user could hold down the trigger and the gun would fire as soon as the pump was pushed forward. On Nelson type guns it was a simple matter of reshaping the trigger or replacing the trigger with an aftermarket piece. On Sheridan type guns a lever replaced the safety and was actuated by a guide system on the pump handle arm. In essence, the device used the safety function to keep the gun from firing until the pump handle was forward.

Along with the direct feed came larger capacity magazines.  Early magazines attached to direct feed guns were simple 20 to 30 round “stick” feeders. This gave way to shorter profile magazines such as the WGP Ammo Box, which held about 40 rounds, and a variety of hoppers made from PVC tubes, etc.  At first, the hoppers were designed to be reloaded from the same ten-round tubes which were used on the early guns.  Eventually, bulk reloading came about, featuring hoppers with large lids able to accept re-loads from large tubes.

Bulk loading allowed for much quicker in-game reloading, which meant players could fire more paint without having to worry about going through a cumbersome reloading process when the hopper ran dry.  Although bulk Co2 preceded bulk loading by some time period, it was probably bulk loading that helped actually bring bulk Co2 to the forefront.  Depending on weather conditions (temperature), a 12 gram Co2 cartridge would give 20 to 30 shots on most guns. This meant having to go through what was a cumbersome process on early guns. Some guns, accessories, etc., were marketed on the idea of efficiency, claiming to get more shots per cartridge and thus requiring fewer changes.  A variety of “quick changers” made their way to the scene, allowing the changing of the cartridge in a matter of just a few seconds. Lever action changers like the Line SI unit, or the Airgun Designs (AGD) Micro CA II made changing cartridges quick, although the player still had to stop firing in order to grab the new cartridge. Meanwhile, on the west coast of the US and making its way east, was the idea of bulk Co2. A seven ounce tank, for instance, would allow 350 to 400 shots before a needed refill – a player could fire even the largest hopper dry without stopping – and refilling the bulk tank was much cheaper than buying 12 gram cartridges. However, some in paintball heavily resisted bulk Co2, claiming it would being an end to tradition, fair competition, and the game itself. Accusations flew that the resistance had to do with a perceived loss of profit margin by those selling the goods.

Even after commercial fields gave in and started allowing bulk tanks, the tournament scene was still strictly 12 gram.  And then the ultimate 12 gram changer came along – the AGD Six-pack.  It was a changer that combined a butt-stock with a spring-loaded, lever action, vertical Co2 cartridge magazine. Switching cartridges with the Six-pack only took a quick activation of the lever. This device was so innovative it literally put itself out of business. Once it was available, there was little difference in playing with 12 gram or bulk Co2, since the Six-pack was basically a “virtual” bulk tank. Without this quantifiable difference, resistance to bulk Co2 finally fell. Ironically, those who sold Co2 found not only was their profit margin higher with the bulk product,  but players were also inspired to buy and shoot more paint.

Aftermarket companies continued to produce a variety of upgrade parts for both guns, such as 12 gram quick changers, rear Air System Adapters (ASA- also known as a “back bottle adapter”) which would allow the use of a screw-in type bulk Co2 tank, and a variety of internal parts aimed at efficiency improvements and smoother operation. Rather than modify existing guns, some aftermarket companies began producing complete replacement bodies with the direct feed already in place. The replacement bodies kits were much more widely available for Nelson guns, probably because the design of the gun allowed the body to be easily replaced by anyone with common tools. Most of the replacement body kits also came with longer barrels, or interchangeable barrel systems, and larger wrap-around type pump handles to speed cocking action. It was common to see these companies selling their kits as whole guns, using the original manufacturers parts to make up the difference of what the kit lacked. For instance, Line SI originally sold it’s Bushmaster with a Nelspot 007 grip frame, as did many other Nelson kit manufacturer’s. On the other side, WGP sold its original Sniper with a Sheridan grip frame.

While it would be a few years (too late) before the Nelson Paint Company would come out with anything beyond the 007 besides some accessories, PMI actually came out with several new versions of their gun. The PMI-1, for instance, had a longer barrel and larger magazine capacity. The KP rifle series were mounted in wooden stocks. The PMI-2 was basically a PMI-1 with a rear ASA. And the Piranha line introduced the company’s first guns with a factory-welded direct feed, and smoother pumping bolt.  Ironically, most modifications appearing on PMI guns were already tried and true “garage” or “custom” modifications by the time they made it to the production line..

As manufacturers began to look for ways to improve the design, they began to move further and further away from the original designs, making little improvements here and there, until their guns were no longer just kits for the originals. Many of the companies selling aftermarket body parts for Nelson and Sheridan guns eventually turned to manufacturing complete guns (the so-called “clones”).  The CCI Phantom appeared in the late 80s and was one of the first to use no original Nelson parts at all on a Nelson-based gun. Not only did it not use original Nelson parts, the parts on the Phantom were pretty much proprietary stuff – in other words, the function was identical, but most of the actual parts were not directly compatible with the original 007.  The early full production Line SI Bushmaster, on the other hand, still had a good deal of interchangeable parts with the 007, even though all of the parts were manufactured by Line SI.

At the height of paintball’s pump era, top-of-the-line guns had outstanding consistency in accuracy and range, and could produce a rate of fire equal to most of today’s entry-level semi-automatics. At the same time, this performance did not come cheap. Top-of-the-line pumps started in the $350 to $400 range, which is fairly steep considering the cost of modern equipment. Part of the reason for this were the laws of supply and demand. There just weren’t that many people buying paintball guns, and the industry was in its infancy.

For two entirely different reasons, both players and field owners alike yearned for a reliable semi-automatic paintball gun. From the early years of the game, efforts were made to create such a gun, but failed to produce a product that could take hold of the market. The Tippmann Pneumatics SMG-60, for example, was not only a semi-auto, but a full-auto paintball gun. However, Tippmann’s use of the less popular .62 caliber balls, and a cumbersome-to-load low-capacity clip-fed magazine stifled the popularity of the gun. Loading the gun required putting balls into plastic clips, then loading the clips into the 20 round magazine. When firing, the empty clips were ejected out of the side of the gun, which required some kind of catching system to avoid loosing them. Field owners hesitated to let the gun mix with the (allegedly) lower performance pumps of the day, despite the fact that some players welcomed an opponent who would be out of ammo after only one short stint on the trigger.  There was another semi/full-auto known as the Model 85. It resembled a Mac-10 and actually used primer cartridges to fire a small caliber ball. The fact that it involved the use of an explosive powder turned most field owners completely off. As a side note, both guns have since become somewhat collector’s items for their historical value.

Meanwhile, early on Palmer’s Pursuit Shop, along with other companies, was working on perfecting pneumatically automated guns. Glen Palmer produced custom Sheridan-based pump guns. His semi-automatics used (and still do) a small lever connected to the trigger of the gun to trip a valve, which directs gas to a pneumatic ram, which would pump the gun following each trigger pull.  Palmer’s guns were custom made, low production, expensive, and rarities at commercial fields. If Palmer had ever gone into mass production, the semi-auto revolution might have happened earlier.

One type of semi-automatic that did find a place in the market for a short time was the double-action gun. Like a double action firearm, the guns used the trigger to actuate the cocking. This meant a long and sometimes hard trigger pull. The NSG Rapide (from the makers of the Splatmaster), The Line SI Advantage (Bushmaster) and the Brass Eagle Jaguar/Barracuda series were all double-action semi-autos. The down side to these guns was the excessive trigger pull. Rapid rates of fire could only be sustained in short burst, as the user’s finger would give out. The trigger pull also made it hard to use the gun steadily with just one hand, since the trigger hand did so much work. Realistically, the guns offered no advantage over pumps.

There were several prototype gravity fed blow-back guns that never quite made it into full production. Blow-back guns function by using a dual burst of gas pressure to both propel the ball, and blow the action back into a cocked position. While some of the guns functioned, they were not reliable enough for regular use. Brass Eagle’s Nightmare Semi-auto, for example, was actually advertised in magazines, and a few copies were reportedly sold. But the company recalled the guns because they would only re-cock under ideal weather conditions.  In other words, the guns required a lot of pressure to operate, and in cooler temps where Co2 pressure drops, the guns would fail.  With hindsight, it becomes obvious that early attempts at blow-back guns suffered from the fact that most people were trying to make them by converting existing pump systems. The main culprit was the fact that those pump systems were already designed to use the available pressure for propelling the ball, and had little or no excess pressure available for re-cocking the gun.

Meanwhile, around 1990, Tippmann had produced a semi-auto only .68 caliber version of the SMG-60 known as the SMG-68. Like its predecessor, it used the same spring-loaded clip system which was cumbersome to reload and had only a 20 round capacity. Like the double action guns, it was more of a novelty, and when compared to the pumps of the day it offered no realistic advantage. However, not too long after the introduction of the SMG-68, Tippmann released the first reliable gravity fed blow-back semi-automatic paintball gun – the 68 Special. And, not only could you buy new 68 Specials for the price of a top-of-the-line pump, but for about half the price, you could send in your old SMG-60 or SMG-68 and get back a 68 Special. Tippmann had overcome the pressure problem experienced by other manufacturers by turning to liquid*. The tanks fitted to the 68 Special had a siphon tube with a weighted end that fell to the bottom in order to draw liquid Co2 from the tank. It was this “liquid” system that gave the 68 Special the ability to operate. In hot weather where Co2 pressure was naturally high, the 68 was able to operate on pure gas, but with the siphon tank, it would operate in nearly any weather.  The downside of this was the lack of efficiency. While high end pump guns were sold on claims of efficiency, the 68 Special seemed a relative gas hog.

*Co2 is stored in tanks in liquid form. In any unused space, some of the liquid boils into a gas and expands into the rest of the space. Since the liquid is heavier, it falls to the lowest point in the tank.  On a conventional (back bottle) tank set-up, the guns are actually operating on gas from the top of the tank. As the gas is used, more of the liquid in the bottom of the tank boils into gas and expands into its place. Since liquid Co2 is more densely packed, when it instantaneously fully expands it produces more pressure than the already partially expanded gas form found in the top of the tank. Using the gas from the top of the tank means a lower pressure with which to operate, but allowing the liquid to expand partially into this gas creates more volume. Conversely, using straight liquid provides higher pressure, yet is less efficient because the gas never gets a chance to expand in the tank and create more volume.

Along about the same time Tippmann was introducing the 68 Special, PMI released their PMI-III (later known as the VM-68). Like the Tippmann gun, it was a gravity fed blow-back. Unlike the in-line design of the Tippmann, PMI’s was what would become known as a “stacked tube” or “two tube” design.  This was very similar in design to PMI’s Sheridan-based pumps, except that the valve system allowed a secondary burst of gas to blow the action back into a cocked position. The PMI-III had a horizontally mounted Co2 tank that screwed almost directly into the valve system. Like the 68 Special, it was another high-pressure gas hog, but did function very reliably.

At this point, the race was on. Due largely to the inefficiency of the new semi-autos, the simplicity and overall performance of pump guns, and the (usual) resistance to advancing technology, the 68 Special and PMI-III did not immediately dominate the scene. They did, however, spell out the future in no uncertain terms – semi-autos were here to stay.

While Tippmann and PMI worked on refining their own success and other companies attempted to take their ideas even further, still other companies charged ahead with something completely different. One of those was Airgun Designs. The idea to overcome the pressure problem was simple – use the same gas to move the action of the gun that’s used to propel the ball. The 68 Automag did just that with what is called a “blow forward” design.  A release of gas pressure pushes the bolt forward and the ball into the breech, then the same gas passes through the bolt to propel the ball. Not only that, the company figured out they could actually use lower pressure if they used a higher volume of gas to propel the ball. To do this, AGD figured out the one concept that other companies eventually came to understand and expand on only years later – to use more volume, the gun must have a larger valve chamber in which to store the gas before it’s released. Ironically, as in the case of the Six-pack quick changer, AGD once again became it’s own worst enemy by designing something that worked too well. The 68 Automag was designed to operate at a relatively low pressure (between 400 and 500psi), however, the trigger design of the gun also allowed it to be fired very rapidly. AGD was one of the first companies to actually advertise a “rate of fire” statistic, claiming in excess of 7 balls per second on early models. Unfortunately this meant the gas system has to be fed by a high rate of pressure (850psi) in order to recharge the valve chamber fast enough during rapid firing. Despite the intention of it’s design, the 68 Automag became a “high pressure” gun because of the way it is used. The buying public knew or cared little about operating pressure and due largely to the high rate of fire, the 68 Automag became one of the most popular paintball guns ever sold, and continues in production today.

Blow-back designed continued to reign as the most simple of the semi-automatic crowd, and several companies attempted to produce such a gun. This included Line SI, whose success with the Bushmaster pump series had built an incredible reputation. The Promaster was a stacked tube design like the PMI-III, but suffered from a need for high pressure, and several design flaws. By the time the problems were addressed, Line SI had lost it’s reputation and closed it’s doors (the owners of Line SI would later emerge as Indian Creek Designs with a whole new line of semi-automatics.) On the other hand Feral Action Sports Technology (FAST) had incredible success with it’s F-1 Illustrator. The Illustrator was designed with a relatively large valve chamber, a higher flow valve system, and light weight internal parts – in other words, the gun required less overall gas pressure to operate, and was not as sensitive to temperature fluctuations.  There were some minor shortcomings to the gun. Among these were a relatively stiff trigger pull, and less consistent range and accuracy qualities when compared to high end pumps.  But unlike the early Tippmann and PMI guns, the F1 was no gas hog, even beating some pumps on efficiency. The gun was (and still is) very usable.

Meanwhile Worr Games products, known for having both a line of Nelson and Sheridan based pump guns, had been working for some time on a system which would lead to one of the most popular selling guns in paintball history. WGP took it’s Sheridan based pump, the Sniper, and converted it to a trigger actuated, pneumatically automated semi-automatic paintball gun – also known as the Autococker. Under this automation system, the gun uses a very low gas pressure fed to a pneumatic ram to cock the gun following each shot. Since the cocking action and the firing are not happening simultaneously (which is the case with a blow-back), the gas is not required to do double duty, thus overall gas pressure is not an issue.  The first Autocockers were converted Snipers. For about $250, you could send your Sniper to WGP and get back an Autococker.  Arguably, because of it’s complexity the Autococker was not the most reliable gun on the market. However, it offered the overall performance of a pump in semi-automatic form, and spawned a complete aftermarket industry as other companies tried (and succeeded) to improve reliability and performance. Eventually, the Autococker became the first semi-automatic which could be purchased entirely in aftermarket parts, without ever having to touch a WGP part along the way. The incredible “upgradability” and personalization possibilities only added to the popularity of the gun.  WGP also made a pneumatic cocking kit for Nelson based guns which used many of the same parts from the Autococker, but the kit was short-lived.

There were many other semi-auto designs which appeared and almost as quickly disappeared in the early years of paintball. Brass Eagle had it’s Golden Eagle, Ultrasport Inc. had the Patriot, and many more came and went. Some worked great while others simply sucked, but they were all eventually replaced by more modern, more efficient, more reliable guns.
Even before reliable semi-autos appeared,  bargain full-featured pumps such as the WWP Razorback had already crept into the market to steal some of the high-end pump’s thunder. The Razorback, for all appearances, offered everything higher end pumps offered at about half the price, so the issue became one of alleged quality and brand name importance. However, in the early 1990’s, when semi-automatics began entering the market at a price competitive with high end pumps, the performance differences were obvious. The dominance of high-end pumps was coming to an end.

WGP, with the Autococker, would not only make the transition into the new market, they would eventually dominate the higher end of it.  On the other hand, Line SI put all of it’s hopes in the ill-fated Promaster, while continuing to sell the Bushmaster pump at a premium price.  CCI, manufacturer of the Phantom pump, took a different route. The price on the base Phantom was eventually reduced to about half of the original selling price, which made it a more than viable alternative to expensive semi-automatics. At the same time, CCI carved it’s own niche’ in the market by creating a retro stock class version of the gun. The stock class Phantom, like the 007, has a low capacity horizontal feed tube, and operates on a 12 gram cartridge.  Several other manufacturers took the same route and work to promote the concept as a “traditionalist” form of play.

As technology and reliability increased, semi-auto paintball guns moved into the position being considered “higher-end” equipment, while pumps were relegated to “entry-level” status.  The one thing that changed this was the entry of Kingman’s Spyder into the market. The blow-back Spyder was the first reliable under $200 semi-auto on the market, and within a short time after it’s introduction, supplanted pumps as the “entry level” gun. This changed the face of the game forever. No longer did new players start playing with a pump and move their way into semi-auto play. Thanks to the Spyder and a hoard of low-cost blow-backs that followed, most players can afford to start with a relatively high-rate-of-fire semi-automatic.  Pumps became known as the equipment of either the “traditionalist” or the poor.  The success of the Spyder also changed what commercial fields used as rental guns. With the majority of players who owned their own equipment using semi-autos, those using rental pumps were at a definite disadvantage. Many fields upgraded to semi-autos such as the Tippmann Pro-lite, which are reliable and tough enough to stand up to the rental process. With even the lowly rental gun now being a semi-automatic, many of today’s players have never used a pump gun.

A new power source was to soon find it’s way into the scene.  AGD lead the way in this new innovation, motivated by the fact that their 68 Automag was somewhat less than Co2 friendly. The Automag would freeze up at the introduction of liquid Co2 – freeze up to the point of not being able to operate for several minutes. Automag owners overcame this problem by jumping through a series of hoops to eliminate the introduction of liquid Co2, and assure the gun only breathed pure gas. The “anti-liquid” solutions included adding expansion chambers where the liquid could expand into gas before reaching the gun, installing anti-siphon tubes intended to suck gas from the top end of Co2 tanks, and using regulators which helped control the introduction of liquid by controlling the pressure going into the gun. Each one of the methods added to the cost of successfully operating an Automag at full speed.  AGD, however proposed and pushed for the use of High Pressure Air (HPA), from early on in the development of the Automag. Compressed air was not stored in liquid form and would not freeze seals and o-rings like Co2. However, it would be several years before HPA would catch on to the point that the price for equipment would become semi-reasonable, and commercial fields would start offering fills.

The biggest advantage to HPA is it’s lack of sensitivity to changing weather conditions, or flutuations caused by the changing amount of gas in the tank. As Co2 is used rapidly, the tank will chill, thus dropping the output pressure. With HPA this was not a problem. HPA tanks deliver very consistent pressure, shot after shot.  The tanks are also easier to refill, since they can be easily topped off, where Co2 tanks will not take a good fill if the tank is warm. One disadvantages to HPA is the added expense of the tanks.  Guns designed to run on standard Co2 tanks will generally operate at whatever pressure the tank is releasing, for instance, 800 to 900psi on a warm day. HPA tanks, however, store gas at up to 4500psi, which is far more than any paintball gun has ever required to operate. That means the HPA system must include a fairly expensive regulator to drop the output pressure of the tank down to something the gun can actually use, not to mention that the tank itself has to be constructed to store much higher pressures.  Another disadvantage to HPA is the fact that it is stored less efficiently than Co2. Co2 is stored in a very dense liquid form. For a given size tank, Co2 will generally power a gun for more shots.

Along side other improvements, barrels technology has steadily advanced over the years. So much of what is advertised is so highly theoretical, it’s really hard to put a finger on what technologies are successful. As far as sales, Smart Parts Inc. (SP) certainly has enjoyed great success. With their “rifled” barrels, SP lead the way in the aftermarket barrel industry. The barrels are not actually rifled in the classic sense, but instead have a pattern of holes for porting.  The obvious effect of the porting is noise reduction. The theory behind ported barrels is that the holes release excess gas so that it will not affect the ball as it exits the muzzle, resulting in a straighter flight path. This theory has been the subject of great debate.

One concept that has been subject of a lot less debate is the fact that paintballs are actually made in various sizes. To compensate for this, most barrel manufacturers produce their products in several different bore sizes, varying only by several thousandths of an inch. A lot of the so-called “experts” in the game claim that having a good paint to barrel size match is more important than barrel length, material of construction, or what kind of porting it has.

Along these same lines, several manufacturers offer breech sizers, to make sure the ball is held in the same place each time it’s fired, and to make sure small balls don’t roll down the barrel before being fired. Palmer Pursuit Shop puts indentations in the breech area of their barrels for the same purpose. Palmer’s guns are very accurate while not being picky about paint.

One of the most unique innovations to come along in barrel technology is the Tippmann Flatline system.  The system uses a curved barrel to produce a backspin on the ball, which gives it a “floating” effect and less drop over a given distance. While you could successfully lob balls an equal distance, the Flatline system allows a flatter trajectory which is useful when playing in areas with overhanging trees. Although backspin has been experimented with from time to time, Tippmann was the first to offer it on a regular production gun.  Unfortunately, the concept relies on the weakest link in the paintball performance chain – the paintball. The Flatline is not as consistently accurate as normal barrel guns, but can be used effectively by a determined player. (read  review here)
Another area of paintball technology where unproved theories fly like moths around a light bulb is “low pressure” operation. Guns operating at lower than normal pressures use volume to accelerate the ball up to speed. To do this, they must have a large valve chamber area to store gas, a valve system that allows the gas to flow very freely, and a regulator to drop the output pressure of the tank down to the needed pressure. Since LP operation replaces pressure with volume, extreme LP operation can result in a serious deficiency in efficiency.

Common theories concerning increased range and accuracy because of lower impact and deformation of the ball are as of yet unproved. However, there are several quantifiable advantages to operating in a lower pressure range. The first of those is the need for less pressure actually combats the “pressure” problems suffered by early semi-automatics. If the gun is always operating below the output pressure of the tank, there should always be adequate pressure to operate. Low pressure operation defeats a good deal of the problems encountered with Co2, especially when the gun operates below the minimum possible output pressure of the tank. For instance, on very cool days a Co2 tank may only produce 600 psi. This would, of course, starve a gun tuned to operate in the more standard ranges of  750 to 800 psi. However, a gun operating at 350 psi would not feel the effect.

There are two other quantifiable advantages to LP operation. Noise reduction is the most obvious. Higher pressure simply produces a louder “pop” as the gas expands upon release from the valve system. The other advantage is less excess gas expanding into other parts of the gun, particularly up the feed tube where it can interrupt the steady feeding of balls. And impeding the feeding is a very bad thing.

In the world of paintball guns, firepower reigns supreme. While a high rate of fire can come in handy on the field of play, from a realistic standpoint, there is not much difference between 7 and 10 balls per second. However, the biggest perceived difference between lower-end equipment and higher-end equipment seems to be the rate of fire that can be attained. High rate-of-fire has become a major selling point for paintball guns and something manufacturers strive for. There are a number of physical limitations in this area, yet (as paintball gun manufacturer’s are discovering) nowhere near as many one might think. As often has been the case, many people apply firearm standards to paintball guns only to discover that those standards aren’t always applicable. While the task of shooting 9 shots per second on a firearm presents a number of difficulties to overcome, on a paintball gun it’s a relatively simple matter. There is no friction/heat build-up, no wear from the continuous explosion of gunpowder, and paintballs are round – meaning they do not require insertion into the bore in any particular direction.

Since the introduction of the direct-feed on early pumps, gravity has been accused of being rate-of-fire’s biggest enemy, yet remains it’s biggest friend. To this day, all but a very few guns are gravity fed. Relying strictly on gravity offers an incredible feed rate if a few obstacles are overcome. When semi-automatics first appeared on the scene, both blow-backs and AGD’s blow forward 68 Automag suffered from excess gas traveling up the direct feed tube with each shot. The excess gas is largely a byproduct of the relatively high pressure at which the guns operate, and the instantaneous expansion of that gas upon release from the valve. This creates a problem when firing rapidly. On open-bolt direct feed designs, the bolt is recessed behind the line of balls entering the gun from the feed tube. When the trigger is pulled, the bolt comes forward, pushes the bottom ball into the bore and fires it away. Meanwhile, as the bolt retracts, excess gas blows the line of balls above it back up into the feed tube just a little. The next ball in line is only able to fall partially back into the breech as the bolt comes forward for the next shot. The bolt then catches the ball in mid-stream, promptly slicing through it, and creating a mess in the gun nobody wants. This problem  limits rate of fire, since the obvious solution is to wait longer between shots to allow the bobbing balls time to drop fully into the breech.

One solution to the problem was to drill holes in the feed tube to release the excess gas. Most manufacturers indeed turned to this idea, but it was only a partial solution at best. Before exiting through the relief holes, the gas still impacted the balls and impeded their ability to fall smoothly into the breech. Once again, AGD displayed a knack for innovation by developing what is known as the “powerfeed”.  In this design, the feed tube is mounted across the top of the gun, forcing the ball to turn a 90 degree angle out of the tube, before entering the breech. The idea is, the next ball in line cannot be blown back up the feed tube, since the excess gas is pushing the ball in a direction against the outside wall of the powerfeed. In fact, the ball actually bounces off that wall and ricochets back into the breech, thus the term “powerfeed”. The powerfeed is now standard equipment on most blow-backs and allows for a very high rate of fire without ball chops.

Closed bolt guns such as the WGP Autococker and Palmer Pursuit guns do not generally suffer from the same “excess gas up the feed tube” problem, for several reasons. In the closed bolt system, the bolt (which in most cases has an O-ring to seal the breech) is forward before gas is released from the valve system, meaning the effect is less pronounced. At the same time, the guns operate at lower pressures, and don’t have as much instantaneous gas expansion to cause such problems.

Another problem to overcome on the road to attaining a high rate of fire was the jamming of the ammo hopper. Left unattended, balls would eventually jam at the opening of the neck of the hopper and stop feeding. This was not really a serious problem on pump guns, since the pumping action itself  lead to shaking up the hopper on a frequent basis. However, it was enough of an occurrence that several companies worked to develop hoppers with specially designed feed channels, etc. meant to eliminate jams. Jams were more frequent on smoother operating semi-automatics. The next innovation in this area involved putting an agitator of some sort in the hopper to keep the balls moving.  Several devices were used but the most successful of these is the VeiwLoader Revolution. The Revolution has a photoelectric cell in the feed neck. The cell senses when there is no ball in the neck (meaning the hopper is jammed or empty), and starts a small electric motor that spins a paddle inside the hopper to clear the jam. This system allows for sustained high rates of fire by ensuring balls are always in the feed tube and ready for use. The system can also help combat the “excessive gas up the feed tube” problem mentioned earlier by keeping the feed tube full and not allowing balls room to blow back up the tube.

Although spring fed magazines were long ago available on several guns manufactured by Tippmann Pneumatics, not until Tagline introduced the TS-1 (later AT-85 by Advanced Tactical Systems) was a high-capacity non-gravity fed paintball gun mass produced. As a basis for a series of Military/Police training guns, the ATS guns use a chain-driven conveyor to pick up the balls from the bottom of the magazine and transport them into the breech. The clip-type magazine holds about 25 rounds and is easily replaceable, similar to changing magazines on the real M-4/M-16 which the training guns are designed to emulate. For realistic training purposes, this capacity works fine. However, for paintball purposes, the clip magazine is fed by either a 60 round magazine in the foregrip, or by a standard hopper on an adapter on the side. The gun was probably the first production paintball gun since the SMG-60 to feature the “select fire” options of semi or full auto.

With more reliable methods of feeding balls into a paintgun, the only real obstacle which remained to ever increasing rates of fire concerned the user. It was possible to make any number of guns fire faster than humanly possible. For some companies, hooking a machine up the gun to pull the trigger proved the guns were capable of cycling faster, it’s just that people couldn’t pull the trigger any faster. One partial answer to problem was the invention of the “double trigger”. The concept behind the double trigger developed from players using their stronger middle finger to “fan” standard triggers. The double trigger allows a more comfortable way to take advantage of that stronger finger. Double triggers started as aftermarket accessories and soon became an almost gimmicky selling point on entry level guns. That’s certainly not an implication that they don’t work, because with the right technique a double trigger can easily lead to an increase in the rate-of-fire.
When a human can’t do it fast enough, call in a computer to do the job. That’s seems to be the working theory behind the next step in paintgun evolution. In the mid 1990’s, PVI hit the market with an electronically controlled paintball gun known (appropriately) as the Shocker. The Shocker is a closed bolt select-fire gun in which the pneumatic operation is controlled by electronically triggered solenoids.  The electronics of the gun allow programmable firing modes such as a multi-shot burst with one trigger pull, full auto, etc., and a rate-of-fire selectable via an internal set of switches. The trigger pull itself is very light, since the trigger only activates a small switch. The electronic control of the functions of the gun provides very consistent velocities, which manifest itself in outstanding performance in range and accuracy. At the same time the gun operates at a very low pressure (about 180 psi) which makes it extremely quiet. Drawbacks to the design? The price (starting just below $600 for the base model) is somewhat prohibitive, the gun weighs a ton (relatively speaking) and using such low pressure means a higher volume usage – in other words, it’s a gas hog. However, those disadvantages are a trade-off whose value becomes evident with use of the gun.
From England, the WDP Angel also made it’s entry into the electro-pneumatic market in the mid 90’s. The Angel is an open-bolt electronically controlled gun with a hair trigger akin to the clicking of a computer mouse. It is now considered among the highest level of paintball guns and it’s price reflects that notion (at basically $1000 and up). Unlike the Shocker, which will operate on Co2, the Angel also requires the user to invest in an HPA system. The gun is capable of different programmable firing modes (which with an accessory kit can be done via your home PC). The Angel LCD even goes so far as to include an LCD panel with a nice digital read-out of the gun’s functions.

The Angel and the Shocker lit the way for what was to come – more electronically controlled guns with hair triggers, programmable firing modes, and digital displays — and the newer guns would improve on efficiency, speed, and weight characteristics. Several aftermarket companies developed electronic upgrade kits for older guns like Autocockers, Automags, and Spyders, giving  them electronically controlled firing modes. As competition provides, prices  continue to drop. Even many of the kind of lower end guns available at department stores now have electronic triggers at relatively low prices, although the old adage “you get what you pay for” still applies.

The production of electronic or “e-guns” may be headed for a roadblock in the near future, depending on court actions resulting from the filing of a patent infringement lawsuit by Smart Parts Inc. Smart Parts started out by suing Indian Creek Designs, which produces the electronic “Bushmaster” series. Smart parts, which has patented the electronic system used in the Shocker, now claims it has the rights to any paintball gun that uses electricity, a switch (for power or the trigger) and/or a solenoid to fire a paintball .  If Smart Parts is successful, they will either be able to obtain royalties from other “e-gun” manufacturers, or bring a halt to their production.

How the Smart Parts lawsuit will effect the industry in general remains to be seen, but some manufacturers are not waiting to find out. Several years ago AGD jumped into the electronic age with the E-mag, and it’s accompanying high-speed ball feeder, the Warp Feed, which claims feed rates in excess of 20 balls per second. However, following the threat presented by the Smart Parts lawsuit, AGD came out with a high speed all-mechanical paintball gun design.  WGP continues to produce their mechanical autococker, as well as an electronic model. For these companies, success is likely to continue regardless of the outcome in the courts. On the other hand, companies which have put all of their eggs into the electronics basket may be in for a surprise.

Note: When this article was originally posted I had apparently incorrectly credited Smart Parts Inc. with the introduction of the Shocker. I have received a number of e-mails (samples here) correcting the mistake. WDP, the manufacturer of the Angel recently won a judgement in the ongoing legal action involving Smart Parts Inc., which may or may not set a precedent. There is a world of information on the web concerning the issue.

The quest for “rate of fire” has continued to drive other advancements in paintball gun technology. Companies continue to promote “rate of fire” as a selling point, with one recently advertising as high as 36 balls per second. Several companies selling E-guns over the past few years have begun to incorporate an “anti-chop eye” — an electronics sensor designed to detect the location of a ball in the feed port and thus keep the bolt from chopping it in half during high speed operations. Tippmann’s A-5 includes a built-in hopper system called the Cyclone which uses an air-powered sprocket to chamber balls in time with each shot fired, eliminating the need for an aftermarket agitated hopper system, and increasing the rate at which the gun can be fired.

How fast will paintball guns ultimately shoot? Some of that will depend on forces outside of the industry… namely, insurance companies. The companies that insure commercial fields set the standards by which the game survives, for without them, there would be no commercial fields. Limiting paintball gun performance in the name of safety is already being done to some extent, and may eventually have a serious impact on the way guns are designed. But for now, it doesn’t really seem to be slowing anybody down.


Some time near the turn of the century, cosmetics became a major selling point for paintball guns, with brightly colored anodizing covering artfully sculpted aluminum gun bodies. While early paintball guns were largely utilitarian in looks, more closely resembling firearms, many modern paintball guns seem to represent a fashion statement on the part of the player. A lot of this began with the Autococker series of guns. WGP’s original Sniper/Autococker aluminum body has so much material (a thicker than necessary body), it’s almost an invitation to a talented person with a mill. With players apparently willing to pay big bucks for exclusive looks, a number of companies now specialize in milling and anodizing work.. In addition, many companies now offer “from the factory” fancy milling in an effort to help sell their product. For the most part, this work is not designed to affect the performance of the gun, but it does offer a weight reduction.

In an almost-opposite-but-much-the-same-type-of-thing occurrence, cosmetic work has also taken a different turn over the past several years in the form of “replica” paintball guns. These are guns designed to look like real firearms, and have gained popularity with some scenario players. Like the multi-colored crowd described above, the cosmetic modifications can be made with add-on parts to an existing gun, or bought whole from the factory, and for the most part, the cosmetics are much more about looks than performance. The cosmetics can also be expensive, with many of the parts being the actual parts to firearms which the paintball guns are designed to emulate.

What direction will paintball gun technology go in the future? Good question. Has the “rate of fire” race topped out? Can range or accuracy be improved considering current projectile and velocity limitations? Are Co2 and HPA the final words in power sources? Will electronics control more aspects of performance? Paintball, is afterall, in it’s infancy from a relative standpoint, yet it has come a long way in a quarter of a century. There’s no telling what we’ll see in the future. One thing’s for sure – just when you think you’ve seen everything possible, someone will come along and surprise you.