Don't feel too bad. I see many hunters do that all the time. In fact, very recent here, I met up with a guy who had 2 different weight grain bullets in his gun! He checked his zero and one was high right about 9" and the 2nd was straight high about 6". I fired 2 myself, just to re-check. I was still zero. LOL!

You learned a good lesson. Also you told on yourself by revealing you didn't get much practice either... but I'm assuming that. You could have used a different gun.

Good luck next time.

iSnipe