Kem1988,
Exactly as Shotgunjones described. I once had a 12ga. Browning Ultra Sporter that was ported. My shooting partners didn't appreciate the muzzle noise, the muzzles would light up at night shooting trap, and cleaning the ports and barrel soot after a shooting session was a pain. My reason for having them was in the beginning I imagined there might be some advantage, I thought they looked cool and everyone else had them, and that was the only way Browning sold their sporting guns. I've avoided them ever since.
I once saw a SxS with barrel ports and extended Winchester type choke tubes that made me sick.
I would search high and low for an appropriate gun without the ports if I were you.
Karl
