For shooting single pigs over a feeder, 5-6x is about right. For trying to bag 2 or 3 over the feeder, it's better to drop down to 2-3x. If you're moving around and likely to scatter them at close range, then definitely around 1-2.5x. For shooting over 150 yards, I find 6x much easier than lower magnification. I think the new S&B 1-8x is about ideal, if you don't mind dropping $3k for a scope, lol. More realistically, one of the 1.5-6x models is about perfect.
NRA Endowment & DSC Lifer