Upgrade your Benelli with the Black River Manufacturing Ported Barrel. When the cartridge is fired, gases push the shot down the barrel and as it passes each port some gas is vented out to counteract muzzle rise and reduce felt recoil. Black River barrels are drilled from 4140 steel instead of 4130 which has nickel in it which makes it softer. 4130 is used because it can be extruded to make barrels to cut down on costs leaving you with a low quality barrel. Black River barrels are drilled from 4140 to ensure the highest quality possible. These barrels come with an extended ported choke which is threaded in Benelli Mobil thread pattern. IncludedBenelli M4 barrelPorted extended choke #5 FeaturesChoke Thread: Benelli MobilModels Fit: Benelli M4, Benelli M104Shell Length: 2 3/4" and 3"Lining: Chrome Linded