Paintball Accuracy

Accuracy in a paintball gun is a blend of many factors. The most important thing to remember is: No single thing makes a paintball gun achieve its best accuracy. It takes many things in concert to give you the best accuracy possible. This is part of the reason that accuracy in paintball is so hard to achieve. The other part is the fact that paintballs themselves are an inconsistent projectile and are subject to an inherent degree of inaccuracy. The following are the main areas to work on to get the best accuracy from your gun.

Paint Quality

The primary factor affecting accuracy is the quality of paint. Consistency in bore size, seam size and roundness are critical to accurate flight. Unfortunately this is usually the least controllable factor in most games and the most malleable in varying weather conditions. Remember that paint quality is often not within your control. You shoot what you have on hand. See the Paintballs section of the tips page for guidelines on selecting paint.

Paint-to-Barrel Matching

The next important accuracy factor is the bore-to-paint match. Once you have good paint, you need to gently guide it on target with a smooth barrel that fits the paint. The usual solution is to use a barrel that matches the paint you happen to be shooting. A barrel system with multiple sizes or inserts will ensure a good match through a variety of conditions.

Having multiple inserts or sizes of barrel helps ensure that the paint is neither too loose nor to tight in the barrel. Too loose, and the paint bobbles in the bore and either rolls out the end, breaks in the barrel or is unstable in flight. Too tight and the ball is compressed and either tears in the barrel or is deformed and unstable in flight.

A simple way to test bore-to-paint match is to take the barrel off of your gun and fetch out a few rounds at random from your case. You should be able to place a ball in the breech and gently puff the paintball out of the barrel. It should not roll out, nor should you have to break a blood vessel trying to blow it out of the barrel.

Velocity

Another huge factor in accuracy is velocity. Consistency is the watch word. The more consistent the pressure, and therefore velocity, the better grouping of shots. Most things that help even out your shot-to-shot velocity will also help your accuracy. This means controlling the pressure and stability of the gas used to operate the gun. High Pressure Air is far superior to CO2 in this arena. If you run HPA, make sure you have a good, consistent regulator on both the output from the tank, and the input into the gun.

If you run CO2, make sure you are doing your best to keep it gaseous, keep it expanding well and not condensing under rapid fire. Expansion chambers are cheap and a decent solution, but a good regulator (like a Palmer Stabilizer) will guarantee you only feed gas to your gun.

Do everything you can to get your shot-to-shot velocity variation as close to zero as possible. Keep your gun clean, well lubed and running smoothly to get the most accurate results.

"Low pressure" operation is is one of the industry's greatest hype campaigns. Again, according to scientific tests by AGD, the acutal pressure of gas hitting the paintball is between 50-125 psi, regardless of the operating pressure of the gun. "Peak pressures above 150 psi tends to break balls down the barrel due to really high acceleration and G forces. If you don't have any way to control the peak pressure behind the ball, the only way you can change it is to go with lower pressure in the air chamber, hence low pressure guns." So unless you are changing the pressure input to the air chamber you are not doing anything to lower the pressure of the gun. Cheap "volumizers" are designed to give greater volume to the chamber once you have that low pressure. They do not lower the pressure in any way by themselves. For that, you need gas pressure regulation, either at the tank level or via an add-on regulator.

Barrel Quality

Your barrel should be smooth and scratch free. This promotes consistent contact between ball and barrel. Another factor is the barrel's trueness from thread to bore, or how straight the barrel screws into the gun. Even a tiny bit of variation will express itself as a consistent strike point that is "off" the aim point. This is largely a manufacturing issue, so buying reliable brand names (J&J, Smart Parts, Dye) is the best solution to this issue.

Materials for barrels vary from brass, to aluminum, to stainless steel to carbon fiber. You may also hear of ceramic barrels. These are actually aluminum barrels with a ceramic coating, and are very effective at remaining "slick" and low-friction. Each material has its advantages and disadvantages. Brass can be very smooth, but scratches easily and is heavy. Aluminum is light, inexpensive and durable, but not especially smooth unless treated. Stainless is smooth and very tough, but heavy and expensive. Carbon Fiber is very smooth, very light, very quiet, and very expensive.

Barrel Porting

Porting is anther often-touted factor in barrel design. Ports are supposed to gradually release that high-pressure gas, allowing the ball to fly smoothly downrange. According to scientific tests by Airgun Designs, about 8-10" of the barrel should be port-free to get the best efficiency out of the gas used to propel the ball. This length gives the best time for the expanding gas from the gun to accelerate the ball without inducing too much friction to slow it back down. Anything more or less, and you will use more gas to get the same acceleration, equating to less shots per tank. Most barrels today have an effective length of about 5-6", so you can deduce the efficiency effects.

Barrel Length

Overall length is largely personal preference. Some like longer barrels with lots of ports, some shorter ones. I personally believe that 11-12" total length is the best; it's long enough to push the barrel tip through cover, but short enough to be compact and easily maneuvered. Be wary of 18"+ monstrosities and their claims of improving accuracy. A longer barrel has nothing to do with accuracy! Remember that these are paintballs, not bullets, and the same rules do not apply.

Barrel Rifling

An ongoing Holy War rages over the concept of "rifling" a paintball barrel. In my experience, rifled barrels perform roughly the same as smooth ones. I owned Armson barrels for years and shot well with them. I now shoot J&J Professional Edge barrels that are smooth bore and love them. Again, the rifling choice boils down to what you like best and what your budget will allow, but it won't make you shoot any more accurately. Click here to read the AGD article on spinnig paintballs and rifled barrels. I think it makes a pretty substantial case for why spinning a ball is pretty much a farce.

The Hammerhead series of barrles has combined "straight rifling" with controlled bore size, which should work as well as any other. Variations in the seam placement when the ball reaches the bore make this no more effective than smooth bores, in my opinion. The seam may be perpendicular in one shot, but parallel to the rifling the next time.

One effect that rifling may have is that of bore-to-paint tolerance. Some claim that internally rifled barrels are more tolerant of variations in paint size or seam placement. This may be true, but may be such a minute difference that it is difficult to measure.

Maintenance

Is your gun running at peak performance every time you step onto the field? You should make sure it is if you are chasing consistency and accuracy. Make sure you aren't leaving old lubricants on the internals, and make sure the seals are fresh and tight. You are trying to make sure that every time the gun fires, it fires the same way.

There is a fine line between cleaning too much and not enough. You don't have to replace every seal and o-ring every time you play. In fact, that is actually counterproductive, since your gun will not get "broken in." You should learn what parts fail and what to watch for and do a visual inspection of all the moving parts after each day of play. This is a critical "control point" for your accuracy. You are responsible for the smooth operation of your gun, and it will show up on the field if you do the proper PMCS. (Preventative Maintenance, Cleaning and Service for you non-military-acronym types.)

Summary

Good paint, good barrel, good velocity, good maintenance. These are the components of the complicated and elusive accurate paintball gun. Don't fall victim to the hype. There is no one-shot (pardon the pun) answer to better paintball gun accuracy. Plan the upgrades to your gun accordingly, know how it functions and you'll find that your ability to hit what you aim at increases incrementally.

Good luck, and I'll see you on the field!