Pinesap
Here is my method. I use a Lohman sight vise but any rigid mount will do. I securly mount the gun, adjust the rest so that I am on bull at 25yds, let 1 shot go. With the gun still in the vise, I put it back on the bull and dial the cross hairs over to where the shot hit. That should be your zero. From that point I would move to 50 and depending on my load I would adjust for elevation and start having fun. You will have some minor adjustments to elecvation and windage but it a fast means of getting to the end when time is not on your side.