Yeah, 450! That'll scare. But at the end of the day, it's your land, dammit and they gotta learn! 
Sad thing is, I know people who think they could just walk up and pet a wild hog

EDIT What did you shoot the 450 with? One clean shot?
@KSM I was in my deer stand at dark when she and about a dozen smaller ones came out of the creek bed and headed to my feeder. I had my favorite rifle with me. An old Remington 30.06 which I customized by floating the barrel and painted the stock a camouflage color. The first shot disabled her and she spun around over and over under the feeder. I was worried she was going to run off into the thicket so I shot a second time. But that is when she started spinning the other direction and did manage to get off into the thicket. I waited in my tree stand for at least 30 minutes making sure I didn’t hear her or any of her brood tearing through the woods. I headed back to my camp to get my tractor and my daughter to go look for her. I drove around and couldn’t find her. I got off the tractor and told my daughter that if anything happened to me NOT TO GET OFF THE TRACTOR!!! DRIVE THE TRACTOR TO THE NEIGHBORS AND CALL 911!!
I found her dead right where I thought she would be in the thicket. It was all I could do to get her drug out and into the bucket of the tractor. My 30.06 is not fancy, but over the last 40 years it has earned it’s “1S1K” brand I labeled it with.
I actually don’t hunt for meat anymore. I run my feeders all year and am always ready, willing and able to teach youngsters how to hunt, but killing animals does not bring me joy. I still sit in my stands several times each year to watch the wildlife but feral hogs are the only thing I dispatch. And it doesn’t come easy. Oh the shooting is easy for me. Sight picture. Breath control. Aim small. Trigger control. These things come naturally for me. But ending an animal’s life has always come with mixed emotions.