LOL "wild" boar arent that tough, most people just dont understand their anatomy or make poor shots. Despite what you've read on the internet, there are no bulletproof hogs.
Looks like the 30-30 packs a bit more power, and in case of using a barnes bullet probably expands to a much larger diameter than a .223 would. Yes i've seen what a barnes tsx .223 bullet will do when used on deer, it works and expands nicely but nowhere near what a .30cal would expand to.
Going off your signature, you're just stirring the pot with your "why not a .223 for elk?". If you want to use it, and its legal go for it.