So in, or just back of the eye socket? Sometimes I've wondered if a 223 55 gr. FMJ head shot might be effective, but at my age and where I hunt, I am sitting in a blind anyhow, not stalking in the swamp. So there's no need to under gun in favor of a lighter weapon.
This sow walked across the field right to left in front of me and out to the feeder, then she turned 90 degrees and looked straight at my blind for about 15 or 20 seconds. It was perfectly still with no wind and I hadn't walked anywhere near the feeder or in that end of the field. Doubt she smelled me and I know she couldn't see me.
She then turned another 90 degrees, broadside to me and pointed herself, I guess, toward her planned exit route back into the swamp, just in case anything spooked her. As soon as she went nose down to eat, I popped her.
I could have taken a head-on shot, but having never killed a hog with a head-on shot, I opted to wait. Also, with the hog in profile, nose down and at dusk, it's hard to tell sometimes where the neck ends and the head begins.
As it was nearly dark, the muzzle flash kept me from seeing the impact clearly, but she immediately spun hard, a full 360, then slowly staggered forward a few yards, then staggered sideways, then fell. It was about in the middle of the field. I must confess that the thought went through my mind that maybe I should put another round in her, but she was at that point a moving target and it seemed she was mortally wounded -- though I suppose I couldn't know that for certain.