By Evil Ed

There are a lot of Theories about a barrel for a paintball gun , here I am going to talk about a few of the theories that I have come across in my research on the subject. But first we must define two words that are commonly misused .........

Ported = A ported barrel is a barrel that has the holes in it 

Rifled = A rifled barrel has little notches or groves that run the whole length the barrel on the inside 

                                                .......... There are many factors that are involved with a barrel so I will try to keep it as simple for all. When your done reading this I hope that the most common questions about barrels like range accrues and noise will be answered for you. ( NOTE THE THEORIES HERE DO NOT INCORPORATE BACK SPIN BOLTS OR BARRELS LIKE COOPER T'S BACK SPIN BOLT OR THE FLATLINE BARREL THAT IS A WHOLE OTHER ANIMAL )

            Ported barrels

The prepuce of porting a barrel is not to make the ball spin but to let air in front and behind the ball to escape so the ball can move freely down and out the barrel.

in a solid barrel as a ball is moving down the barrel the air in front of the is being compressed witch can slow the  ball down at the same time if the barrel is 12" or longer the air behind the will turn into a suction like in a syringe this only will happen in long barrels for the CO2 stops expanding after 8 to 12 inches ounces the air stops expanding the ball acts like a plunger in a syringe and with no place to draw air from it slows the ball down. ( If you take a syringe with the plunger down cover up the hole in the end and pull the plunger up you will feel the suction granted it is not this bad in the barrel but it is there) so by porting the barrel the air in front of the ball gets forced out the holes so there is no or very low pressure in front of the ball and when the CO2 stops expanding behind the ball the hole let air in the barrel so there is no suction made in the barrel  

Now I know some of you are saying that the holes start 6" down the barrel this is ok the CO2 is expanding so fast that only a very small amount of CO2 is going to escape out the holes so it won't make a real difference .

A side note is that because there is no pressure behind the ball there is no big pop or bang when the ball exits the barrel hence the reason posted barrels are so quiet. 

            Rifled barrels

The prepuce of the rifled barrels is very similar to the ported barrel an that it help the air pressure in front and behind the ball. but the rifled barrel also helps the ball move a little fast out of the barrel because with the groves on the inside there is lest surface area for the ball to rub up ageist . (Lest friction = faster ball) the groves all so help keep the ball striate for the air that comes out the groves before the ball like an air rails to help guide the ball.

But there is still a lot of pressure behind the ball so it makes a load pop/bang when the ball exits the barrel.

            Range / F.p.s. 

Range is one of the biggest question. People ask how do I get more range ? Well the we all know that if you up your F.P.S. that you will get more range BUT think about this the faster a ball is move the more air residence there is in front of the ball because the ball is compacting the air front of it making the ball slow down faster witch is why you get the range but the ball almost never breaks O yes don't forget you are using more CO2 to do this to. But if you lower your F.P.S. you may not get the range but you use less CO2 and with less residence in front of the ball and it will hold it's speed longer so its more likely to break. 

The other thought for more ranger is just add a longer barrel . This is not true for once the CO2 stops expanding the friction of the ball in the barrel will slow the ball down witch is why you will need to turn up the velocity on your gun What a longer barrel will do for you is make you more accurate for the simple fact that the ball is exiting the barrel that much closer to the target sounds dumb but true a 12" barrel will shoot more accurate then a 10" because the 12" is 2" close to it's target.

Now a word about paint 1st always match your paint to your barrel we all know this But if you don't here is why we match paintballs to the barrel if the ball is to big for the barrel then the ball has a hard time running down the barrel and will most like break in the barrel if it's to  small for the barrel then the ball will bounce inside the barrel plus you waste a lot of CO2 with all the free space around the ball .Now what about the weight of the paint ? This is something most of use don't think about but think about this take a ping pong ball and a golf ball and throw them the golf ball will go further the same is true with paintballs a heavier ball will go further but the heavier ball will need you to arc the shot a little higher