YOU CAN: lower FELT RECOIL by re-directing the gasses/energy impulse via porting, reduce muzzle flip, increase recovery time & decrease time between shots & is why you see porting on many race guns.
Porting does come with a cost of increased noise/flash/velocity loss & a danger of frying your face if fired with the ports facing you. I had 2 Rugers (a 5" 357 Redhawk & a 3" sp101) get the Jack Weigand hybra port package, 4-5 in line holes from muzzle to breach/ action,trigger work,timing,bead blast finish, new sights, etc. YES they shot faster/smoother/more controllable, BUT you were not popular at the range & I broke an overhead light at an indoor range. If you fired it straight up without eye protection you would likely be blind. They have a place in competitive shooting, not so much for S/D IMO.