While I would never zero a rifle without shooting a group, those with a supremely accurate system or low ammo budget would be keen to watch the NSSF video on zeroing your rifle in two shots.

The key is to hold the rifle at the point of aim and to then move the cross hairs to the first shot, rather than view the target and make the click adjustments. While field-expedient there are issues with this method, especially if the cross-hairs have a long way to travel on the grouping.

Personally, I would only use this method as the video implies, checking zero from one season to the next where there would be minimal movement.