My brother just bought a mossberg 500 for HD it came with the breacher barrel. As he doesn't need to bust any doors open what would be the best ammo to use in it. Will the ported end need any consideration in what he decides to use? I suggested 3 inch mags 00 buckshot. I just don't want him to use anything that might do any damage to the gun and I don't know a damn thing about that type of barrel. I told him ya'll were the experts and would be the place to ask. Thanks in advance for the help.