Yes, my father and I got 8+ one time. I had a .308 semi and he had a 12ga Semi. We had just spooked a group of pigs off a feeder while driving by in a vehicle. Drove on past...waited a few minutes...quietly snuck back to the feeder on foot, got in position, and then set the feeder off using the test timer. Sure enough...couple minutes later here they all came back in. Now, the feeder was in a hog panel fence enclosure about 40ft square to try and keep hogs out...but there were a couple of places where the hogs had managed to get through and or under the old fence. We let them get settled down and I opened up first with a shot from the .308 to ensure I got the 2 biggest ones that I had waited to line up...then I got one or two more in the panic that followed. It was all a blur really (despite the few holes in the fence they all made quick work of getting out). He got several with the 12ga. Some I think we both made hits on actually. At least a couple made it a hundred or more yards though from hits with only the buckshot, and we didn't find those until the next day. Dad and I still talk about that time! We were both amazed at how fast you can empty a semi 12ga :) I think the hogs were too....
That situation made me think about setting up a good fence around a feeder years later at the deer lease and having a purpose designed entrance to the enclosure that was lined up with my deer stand. Pop the first one and then just aim for the gate. Never got around to trying it out though. Of course you could just rig a gate to close on them, but what fun is that :) Actually, that's probably a lot of fun too.