Our customers often come to us with technical questions, and barrel porting is a big one.
What does barrel porting do?
Barrel porting does several things, but its base function is to vent excess air from the barrel as a paintball is fired. As with all moving objects, paintballs displace air as they are accelerated into motion. Because of this the paintball must push the static air in the barrel out of the way as it moves down the bore.
Without porting, all of the static air would exit the end of the barrel exactly as the paintball itself would. You can experiment with this by removing the front of a two piece barrel and using the un-ported back. By having no porting you will notice a very loud sound signature and a very heavy direct puff of air – Make sure you are pointing the barrel away from yourself and anyone else when testing this.
What porting does is to vent that static air in an effort do preform several actions:
1- Quiet the sound signature of the paintball gun – By dissipating some of the air out of the porting the sound signature is reduced, making the gun quieter.
2- Reduce turbulent or compressed static air pressure – By porting the barrel we reduce the “back pressure” that exists in the barrel. Reducing this back pressure is important because paintballs are much softer than many other projectiles and their surface deforms as the ball is accelerated. You can think of the paintball like a tiny water ballon, as you rapidly accelerate the ball air pressure on the front of the ball will “cup” the face of the ball which can cause the ball to catch turbulent air upon exiting the barrel. This can be seen often with older or poorly stored paintballs. Because the balls are softer a player can observe them flying straight then suddenly taking a sudden hook in an unpredictable fashion. This happens because the ball’s surface has caught air, and acted upon the ball pushing it away from a straight path.
3- Manage efficiency – Barrel porting also effects the air behind the paintball, more porting allows air behind the ball to escape more quickly and can reduce the air’s ability to propel the paintball reducing efficiency. This is why most barrels have a 6inch to 8inch “control bore” which is the solid part of the barrel toward the paintball gun. This area acts as the acceleration zone for the paintball making sure all the air that the paintball gun puts out is put to good use before it is allowed to escape from the porting.
How much porting is the right amount?
Unfortunately there is no unanimous “right answer” to this question as barrel manufacturers have been attempting to find this answer since paintball became competitive. The key is to try several barrels on your gun if possible and see which one works best for you in a balance of sound, accuracy and efficiency. If you cannot try several barrels, we suggest you purchase a barrel from a trusted manufacturer.