I use a .308 M7 Remington for about everything including hogs that I hunt now days, when I ain't hunting with one of my handguns. Yeah, it'll stop ANY hog. I shoot a 140 Barnes X bullet at close to 2900 fps, plenty of penetration and energy for any porker I've every laid eyes on. I would use a controlled expansion bullet, but heck, I've found that even my Nosler Ballistic Tip 150s penetrate pretty danged well. I shot lengthwise, stem to stern or rather stern to stem through one this season. The hole in its throat was pretty impressive on exit after shooting through over 5 feet of deer and through the ham. I'm beginning to think the Barnes unnecessary on hogs, but it's good insurance I reckon.
.308 is all you'll ever need in Texas and most of the US, frankly. Oh, some say a .300 mag is best for Nilgai. If I had the money for a Nilgai hunt on the King or Kennedy Ranches, I probably could buy a bigger gun, but I think the .308 could do it, frankly. I have a 7 mag if I thought more was necessary. that thing is a cannon, though, and I prefer my little .308 for normal game. Hogs may look impressive, but they're normal game to me.