Not a good idea - Bushnell Magnetic Boresighter Rifle Scope Accessory

Great product. One major problem. You cannot repeat your settings. Since there is no arbor to center the boresighter on the muzzle, every time you use it you get a different alignment of your reticle.
Pros: easy to use
Cons: no fixed arbor. No repeatability.

This review was written in the old system and had content requirements that are different than reviews written today.