In firearms the term ported relates to holes that are precision drilled into the forward part of the barrel and slide on pistols, to divert a portion of the gases during shooting in order to reduce the tendency of the revolver, rifle or pistol to flip upwards.
Porting is most commonly used on shotguns, where recoil makes rapid firing difficult. Indeed, even single shots of magnum strength loads alone are uncomfortable for all but the most seasoned shooters.
In most instances, porting does nothing to enhance the accuracy of follow-up shots but rather make larger calibers more bearable.