You are gonna be jump shooting so best to use a slug in the chamber backed up with buckshot. I would say 00 as opposed to 000, the 00 will penetrate the "shield" better.
Usually when you stalk hogs you are most likely to catch them in the bed, when they hear you they will get up and stop momentarily to look at you. If you are quick enough you can get a standing shot and thats when the slug is the right choice. IF you miss with the slug, which is most likely
if he is running, you can wack him with the buck shot. In the cover them suckers run like a snipe flies===hard to hit.