One thing you will learn quickly when you play paintball is that all paintballs are not created equally. All paintballs are available in various size calibers, though the difference is virtually impossible to tell by simply looking at one paintball compared to another.

However, the caliber of the paintball does indeed make a big difference once the ball is loaded in your marker or paint gun. Even when you know you are using the correct sized paintball for your paintball gun, paintballs can become warped due to heat or cold exposure and other improper storage techniques.

There is an easy test to see if the paintball is the correct size for the barrel on your paintball gun. Take your barrel off your paintball gun and gently put a paintball in one end of the barrel or the other. Hold the barrel up and tip it vertically, if the paintball simply rolls out of falls out, you have a paintball that is too small for your paintball gun barrel. If the paintball stays in the barrel and you blow on one end of the barrel and you can't get the paintball out through creating manual air pressure, then your paintballs are too large and they will probably burst inside your barrel during play. If your paintball does not roll out of the barrel but you can blow air through your barrel and get the paintball to come out - congratulations you have perfectly fitting paintballs.

If you are in the middle of a game and you discover this, switch out your barrel to one that will fit your paintballs and continue playing, this is why it is a good idea to always pack along an extra barrel or two in your field kit.