Shoot ON the shoulder, not behind it, and use a controlled expansion bullet. There is nothing behind the shoulder, but guts. You might clip the liver, but there's no lung there, it's all under the shoulder. That story sounds like poor shot placement in possible combination with a fragile bullet. A 170 grain standard .30-30 should be more than enough for a 250 lb hog, though. A 150 would perhaps be a little light. I'd shoot the rather excellent Nosler partition in that caliber, myself. One comes my way and I'm armed with my .30-30 Contender, I'll put a Ballistic Tip on him, though. Only thing I've shot with it so far is 5 deer, none of which went far.
I've seen 7 mag with a fragile 150 Sierra Game King fail to fully penetrate a 370 lb hog on a shoulder shot. It went through and stuck in the gristle on the off side. It killed the hog instantly, though. With a Partition, not a problem with that cannon. A lot of it is proper bullet, though. 7 mag is a little overkill, neadless to say, but I'm thinkin' of setting up my 7 just for night hunting hogs after this deer season for two reasons. One, the scope I have on that gun is just awesome in clarity and light gathering. On a moon lit night, I don't even need a spotlight, almost like night vision.
Second, I ain't using the gun for anything else. LOL I got over my magnumitis years ago and went back to normal calibers for deer and hogs. But, even if I don't shoot full power loads, I can down load the thing to 7x57 or .280 Remington levels. I'll keep it full power, though. It ain't THAT "too much".
I'll load some 160 partitions for it and live happy. I had an SKS set up with a scope mounted spot and a lighted reticule scope, but I like the scope on my 7 a lot better and that SKS really works better with iron sights as a knock about truck gun.