Mossberg Shockwave Ported Barrels - Mossberg Model 590 Shockwave Magnaported 12ga Shotgun barrel with Hi Viz Fibber optic Green sight. These 14 barrels feature 22 port holes to greatly reduce muzzle jump and recoil on these self-protection firearms. These barrels fit all Shockwave model shotguns. These cylinder bored barrels are manufactured in the USA with a Matte Black Finish. A must have barrel if you own a Shockwave and want to reduce recoil substantially!