The Vang Comp Systems (VCS) Remington 870 includes the basic gun with an 18.5-inch VCS barrel, LPA rear sight, VCS front sight with tritium insert, a black synthetic stock, the VCS safety, and VCS magazine follower. The gun is refinished in tactical black. The critical modifications are to the shotgun's barrel. These include the back-boring of the barrel from the chamber toward the muzzle end and creating a choke. The compensation ports are the most visible and signature feature of the VCS barrel. When the gun is fired, a portion of the gases from the burnt powder exiting the muzzle is vented upward through the ports. The redirected gas flow minimizes muzzle rise as much as 90 percent and felt recoil by at least 15 percent, allowing for a more rapid recovery time between shots and increased accuracy. The ports also reduce muzzle flash and help in retaining night vision. Another feature of the VCS barrel is the longer forcing cone, which allows the pellets to flow smoothly from the chamber to the bore and prevents the pellets from bunching up in the barrel, thus reducing turbulence. Also, pellets are less deformed. The operational outcomes of the VCS modifications are greater accuracy, reduced recovery time between shots, and less recoil.