Black River Manufacturing Ported Benelli M4 12 Gauge Shotgun Barrel 18.5 in Chrome Linded Black

Black River Manufacturing Ported Benelli M4 12 Gauge Shotgun Barrel 18.5 in Chrome Linded Black. 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 Manufacturing 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.