I use cardboard backers from appliance boxes usually. Then white paper. Stick one 3” target in the middle. Stick whatever targets I need towards the edges.
On the bench, 160 yds away, I sit the rifle on bags.
Remove the bolt.
Look from breech to muzzle while centering on the middle of the white paper.
You can visually see the round of the bore at both ends, just get them centered to each other visually.
Without moving the rifle, lift up your head to look through the scope.
Adjust the crosshairs or dot to the stick on target in the middle.
Check a few times, adjust if needed.
Load and fire.
Then adjust to the impact point.
Generally on the target sheet in one shot, generally adjusted in 3 shots.
It takes a bit longer if I’m using a lower or higher velocity load and/or a 20 moa rail, depending on what the scope was last on.
I fine tune as I go through the charge weights of whatever loads I’m shooting.
Been doing it like that for a long time. Recently swapped scopes on one and wanted to set a 50 yard zero. Used the same procedure at 50 yards, and my first shot was about 1 1/2” to the right of center. Fine tuned from there.
Gotta be aware of how much in inches your scope clicks move. A short range zero may not be on paper at distance if your target size at distance is small.
This is an idea of how much surface area I use. 6x scope view at 160 yds.
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