What does a bigger barrel do?

Longer barrels are quiter for the most part. A 12 in. is my favorite. Its just as accurate as a 14 or a 16 but you can get closer to the bunker.

most barrels 14inches and under have similar performce due to lenth, anything going over 16 inches is a waste becuase it takes more air to power the ball out which takes more air.  And a longer barrel will not add distance so dont think a 21inch barrel will make u a "sniper"

Longer barrels are good for poking through brush in woods play or leaning against bunkers on an airball field. Yes, anything past 16" will decrease performance. A good quality barrel between 8 and 16" will shoot the same. If the 14" version of the barrel you're looking at has more porting than the 12", then it will be quieter. I think 14" is the perfect size. I play on a field with air bunkers and I even use my 14" front when playing the snake.

Daron wrote: I like the 14" size.. But as said.. longer barrels dont mean more range/accurasy.. But, a barrel in the 12"-16" range is preffered by most people because its ok for both maneuvering it around(longer barrels are harder swinging around in the bushes) and to clear covers when firing.. A side note.. Most people thinks that a longer barrel makes you use more gas/air.. But the tippman markers use the same amount of air no matter how you adjust the velocity screw.. The screw just decrease/increase the turbulence in the air flow, making it more or less effective.. And if you want to make co2 more consistent, try a palmer stabilizer..

Just to add a bit to Daron's post. I don't understand where this idea arose that a longer barrel uses more gas! The ball is accelerated to velocity in the first 6 to 8 inches of barrel. That is part of the reason you usually see no porting on barrels until that point. After that the ball is coasting. Even with close matches of paint diameter to bore diameter there is virtually none to ever so slight contact of the ball to bore. Drag in the bore, excessive contact of the ball to the bore, doesn't slow the ball but imparts undesirable spin...a much more detrimental condition than a few feet per second less velocity. If your paint isn't curving then it is not likely that there is any detrimental bore contact...no matter how long the barrel.

Unlike a firearm with an excessively long barrel, the extended length of a paintball marker barrel does not cause drag or friction to slow the velocity.

What a longer barrel will do for you is allow you to reduce your exposure by leaning it into the bunker or, as someone else here said, stick it through the brush to better fire undetected. I also can help with instinctive aiming as the longer barrel becomes easier to point.

The longer barrel is usually more quiet. Longer barrels with many small porting holes after that first 6" to 8" acceleration section provide the lowest levels of firing noise.