Joe...Here's what you do....Make sure all screws are tight, use ammo that you know groups well...

Put a target up at 100 yards, shoot 2 shots....
Adjust scope 4 inches right and 4 inches up, shoot 2 shots...
Adjust scope 8 inches left, shoot 2 shots...
Adjust scope 8 inches down, shoot 2 shots...
Adjust scope 8 inches right, shoot 2 shots...
Adjust scope 4 inches up and 4 inches left, shoot 2 shots, and these 2 should go into your 1st group and you should have shot a square around your initial 2 and final 2 shots....

This lets you know that your scope is tracking well and returning to zero when put there...The times I have done this, I didn't have to go all the way around the square if the scope was bad, it showed up pretty quickly.... Good Luck