Barrel

From Airsoft Community Wiki

The Barrel of a weapon is the tube through which the rounds are discharged. Different weapons have different length barrels, and they are available in a variety of widths.

Barrel Widths

The width, or caliber, of a weapons barrel generally refers to the internal diameter. In most stock Airsoft replicas this is 6.04mm, but barrels are available in sizes down to 6.01mm. The smaller the internal diameter, the closer the barrel is to the diameter of the BB, so the tighter the fit is. Because there is less space around the edge of the BB, less air can escape and the round does not rattle around in the barrel as much. Because of this, the use of so called 'tightbore' barrels generally results in a slight increase of accuracy and range.

Barrel Lengths

For a list of common Barrel Lengths click here

The longer the barrel of a weapon, generally the more accurate it is. This is because the BB is held in a stable path for longer, and so leaves on a better trajectory relative to the orientation of the barrel. This is why sniper rifles and long-barreled weapons such as the M16 or AUG and other Bullpup rifles are generally more accurate than their short-barreled counterparts like SMGs.

Most weapons will benefit from adding a longer barrel, but sometimes a problem called 'suckback' can occur. This is when the cylinder cannot supply a volume of air great enough to accelerate the BB all the way down the barrel. Therefore, as the piston reaches the end of it's stroke the BB is not yet out of the barrel. This causes a slight vacuum effect, especially in tightbore barrels, as the BB tries to pull more air out with it. The problem can be resolved by using a larger (bore-up) cylinder.