I’ve learned a trick to help you when bore sighting a rifle that has a removable bolt that allows you to look down the barrel from the chamber end – It’s called Naked Eye Bore sighting and can be executed without additional tools.
Bore sighting is used when changing or adding optics or verifying your zero on a new rifle or after a period of storage, change of ammo, atmospheric/elevation changes, or other circumstances that might affect your previous zero.
Before using the Naked Eye technique, make sure your action is open and the chamber is empty with no magazine – or magazine empty if not removable…always check twice. In the accompanying video, I’m using an AR-style rifle. The upper is removed from the lower after the safety check, and the bolt carrier group is removed from the upper receiver.
-Use sandbags or a similar base to rest the upper (or complete rifle if using a bolt action) – something that provides stability that the upper or rifle can be “nestled” into.
-Pick something about 25 yards in the distance to “sight in”, or look at through the bore, then look through the optic to see if you have a co-witness (if the sight “sees” what you can see through the bore).
-Make the appropriate adjustments to the sight to zero onto the target. If you have a backup sight or optic, make the necessary adjustments to it as well.
-Fire a shot, or a small group of shots to see if you have an accurate zero. Make appropriate adjustments to correct if necessary.
-Once zeroed at this range, shoot at incrementally farther targets until an accurate zero is reached. I usually go out to 50yards next – I like to use a 50y zero for .556 out of my AR’s – this gives me good ballistics from 50-200y with my ammo and the Low Power Variable Optics I like to use, as I have bullet drop hash marks from the 100-200y mark out to 600y (One of my favorite LPVO’s is the Vortex Strike Eagle – which is the one you see in the video).
By using this technique, I’ve saved a lot of ammo and time through the years with many different rifles – when done properly, it’s bound to save you time and ammo!