[cowgirlone]

I'm afraid I won't be of much help.....we always shoot ours in the front. I try to vision an X on their forehead from the ears to the eyes. Then shoot just off center to the left, not exactly in the middle of the X.
Also, it might help if you are a few feet away, give the sow a small amount of grain to eat to keep her head in place.
Hope it goes better for you this time.