The thing with my group was that it was made with a rifle that should really be classed as a clinical intrument. I have a hell of a lot of respect for a man or woman who can shoot a springer well at any range, I'd like to think I used to be able to do it but these days? I've become too lazy with these new fangled precharged rifles.
Coincidentally I didn't zero at that range. We marked a tree behind the backstop with some tape and used it as an aiming guide, I found that a small lump sticking out the side of the tree was an ideal aim point at the time taking into account the wind that was present that day.
Garrick