This is what I used to do, I'm a tac, not exactly ideally skilled for ground pvp by any means, but I would arm myself with a sniper rifle to score a quick knock back effect, then run up to my opponent, often circle jerking, with dual pistols. If it didn't kill them, usually the said player would get in such a panic, that they could literally be chased around the map until you get a kill. This worked like gold until I reached the Admiral Upper tier area and people know how to play. The story was quite different when I sniped someone, ran up with dual pistols, then the moment he gets up, he takes out his bat'leth and stabs me, then a teamate snipes me, vaporized, dead.
Dual pistol combatants are heavily vulnerable to melee and physical attacks, as I have just discovered. My guess is that is why many of the experienced players who posted don't recommend running with dual pistols. Maybe an engineer could pull if off, but tacs are much too squishy.
I have come to the conclusion that in the upper tiers a tac must learn to love his sniper rifle and hide.