trouble with an EoTech 512
Recently put an Eotech 512 on AR. Zeroed it at about 30 yds.Decided to add a BUIS,which forced me to move the 512 forward on the rail. Now the Eotech is all over the place no matter which way I adjust it.I have checked the mounting on the rail..it's square and seated properly.
Two questions: 1.) By moving a pre-zeroed red dot optic on the rail,typically how much does that change earlier zero?(I have made BIG adjustments on elevetion / windage to try and correct it but to no avail.Everything goes to left shoulder area when using a B27 type target.Aim point is center of head.
2.) Once BUIS is zeroed,am I correct in thinking there are really two zeroing goals here? One for each,regardless of how they co-witness?