Have hunted them with a T/C Hawken .50 during the HAM (handgun, archery and muzzleloader) season in Arizona, in Texas more than once with various rounds while hunting other game, and also took one in Sonora, Mexico with a 7x57 during a Coues deer hunt. All worked fine--and am not surprised than just about anything would work well.
As far as eating, have had mixed results. I suspect they're one of those animals that have a chemical that some people's taste-buds don't like--which happens with pronghorns as well. Most people think pronghorns are among the best-tasting game when cooled quickly, but also have a good friend who hates to eat 'em, even when everybody else likes the same "goat." He says they taste like "dog food" to him, but have often wondered how much dog food he's eaten.
The best-tasting javelina I've eaten was the one from Sonora, which was killed just before Christmas, where javelina tamales are a tradition during Navidad. They were great! But have also had javelina that weren't so good, even though taken good care of, including removing the scent glands.
One of my long-time friends is Don Thomas, the well-known bowhunting writer, hunted them in Arizona for some years. He's also a very good and avid game cook, and years ago wrote a piece on cooking javelina. He suggested a 2-liter bottle of cheap red wine as the primary "ingredient"--which the cook should drink before attempting to eat javelina....
