There are 3 ways to sight in a red dot sight without shooting to save bullets and time zeroing. We're going to share these methods but we highly recommend live firing to refine and confirm the zero afterwards.
Top 3 Methods
Zero the iron sight from previous range trips, then slave any red dot sight zero to the iron sight. Anyone can do this fairly quickly without firing a shot, and people can do this at home or on the range.
Once the fixed iron sights are zeroed, just leave it as is for a zero reference point.
Any time when the user decides to swap red dot sights, simply just dial the windage and elevation adjustment close to the iron sights without shooting.
Zero New Optics To A Previously Zeroed Optic
This is the same idea as slaving the zero to the iron sight recommended above.
If there is rail space available, mount the new optic behind the currently mounted optic (Zeroed), and overlap the dot as close as possible.
Make sure to dial down the red dot brightness setting to see the precise dot. Same thing for any ring type reticles.
Highly recommend seeing the zeroing process through a magnifier scope to see fine adjustments, then confirm the zero with live ammo.
Laser boresight provides a "Ball Park" zero for an new optic if it's completely off. The purpose is to get the dot as close as to where the bullet will hit first, so the shooter doesn't waste time and ammo trying to find the shot groups on paper targets.
This method is helpful for pistol red dots.
Read More: How to use a boresight
Features MidTen Laser Boresight
Why Confirm The Zero With Live Ammo?
Confirming the point of aim is point of impact ensures accuracy of the firearm, it let's the shooter feel confident of their weapon systems, and it's every shooter's responsibility to do.
Sending rounds down range while there is POI and POA difference will pose a danger especially in personal defense or other real world situations. The consequence of bullets hitting something else other than where the dot is pointing can be life and death.
Please be responsible and always confirm the zero with live ammo.