Porting, which refers to the addition of holes near the end of a shotgun’s barrel, can be a good addition to your home defense or sporting shotgun.  There are some drawbacks as well, and this article addresses both.

FN Herstal Tactical Police Shotgun

The porting of the FN Herstal pump action tactical police shotgun can be seen near the end of the barrel.  Porting comes standard on this shotgun, although the barrel of just about any shotgun can be ported by your local gunsmith.  There are also barrel porting services where you can ship your barrel away for porting.  These include Mag-na-port and Gander Mountain.

How Porting Works
Porting consists of adding holes through the shotgun’s barrel, near the end.  These holes are placed along the upper sides of the barrel by a gunsmith (don’t try to drill them yourself!).  When the shotgun is fired, some of the hot gases will escape through the port holes, rather than through the muzzle.  Since the port holes are near the end of the barrel, there is virtually no effect upon the speed at which the shot or slugs exit the shotgun.

Pros of Porting
Porting results in a reduction of recoil and a reduction in muzzle climb.  The recoil reduction comes from the fact that some of the hot gases that would normally help propel the shotgun backward against the shooter’s shoulder (recoil) are instead directed out of the port holes.  Similarly, the reduction in the tenancy of the muzzle to rise when the shotgun is fired (also referred to as muzzle climb, muzzle flip, muzzle lift, etc.) is reduced.  This is because the hot gases exiting the port holes will help push the barrel back down.  The net result is that porting results in a gun that recoils more softly, and stays on target better.  This can be especially beneficial for recoil sensitive individuals.

Cons of Porting
Porting is not appropriate for every shotgun, however.  Porting increases the amount of noise heard by the shooter and those standing next to the shooter.  Porting also results in a more visible flash when the shotgun is fired.  Both are the result of having the hot gases from the combustion of gun power exit the barrel through the port holes, rather than through the muzzle.  The extra noise is primarily a concern when the shotgun is fired for sporting, rather than self defense purpose.  The extra flash, however, could be an issue for self defense at night, since it may worsen the effect upon the shooter’s night vision.  The hot gases which exit through the port holes can also cause burns, which may be either a benefit or liability if firing the shotgun in self defense at close range.

I whole heartedly endorse the porting of shotgun barrels, and have multiple shotguns with ported barrels.  My home defense guns, which I fire regularly at the range have ported barrels.  I don’t mind the slight increase in noise that I’ve noticed, nor the flash.  I also know other gun owners who feel differently, so barrel porting is a decision for each person to make.