Hogs are toguh, a 243 can do it, but 30-06 is safer bet.

My vote also goes to the .30-06.
Some of those feral hogs can weigh in excess of 500 pounds.

It depends on how you plan to hunt. The .243 bolt-action will be adequate if hunting over bait and you have leisure in choosing the shot. The .30-06 pump will be better if shots at running pigs are possible. In either case, shot placement is key. Like others have stated, pigs can be tough to bring down.

I would go with the .223. My friend in S. Texas hunts with a .223, just don't aim for the chest. Go for the neck. If you aim for the chest, that bullet will get stopped in its tracks by the armor plate.
P.s. If you want to have some fun, go after them with a bow. The first animal I ever killed was a +150# boar in S. Texas at 16 yards. At tonne of fun. But I must add, make sure you have that .45 close at hand and loaded. They do charge.

Don't know your hunting "method", but the Marlin is quite sufficient for "pigs".
Iron sights, lever action, short carbine style offers low recoil which helps with quick follow up shots. Quick target reacquisition with iron sights and easy maneuverability. Marlin's the way to go!

How do you plan to hunt them? The 740 is not known for its accuracy, but being a semi-auto would have the better follow up shots. The 700/243 is known for accuracy and would be better at longer range. The .243 with 100 grain bullets and good placement would effectively dispatch them. If your style is more "fast and furious", I would opt for the 740/30-06.

Thanks Quinton. Just noticed the original post listed a Remington 740 semi-auto. My bad, misread it to be the 760 pump-action. I've had great success with shooting multiple pigs up close with a scoped bolt-action so action and sights are not as important to me as is the projectile size and construction. Going with larger bullets is my preference for pigs.

Use the .243 and make a well placed shot. The 30-06 would be better past 200 yards but you should have a closer shot than that.