I have a brand new Bushmaster M4 "Patrolman's" Carbine which has yet to be fired. I did try and bore sight it with a laser bore sighter and it appears the laser is pointing way low and no matter what I do I can’t line up the detachable handle sights, the red dot rail mount or the magpul rail mount back up sights. Looks like everything would need to be raised from the rear but there is simply not enough adjustment on anything to accomplish this. All the sites are consistent with each other just Not with the laser bore site. Rotating bore sight in chamber yielded no difference and the chamber and barrel are spotless. Appears that the difference is approx 5 inches low on laser. I did remove bolt from upper and lined up the barrel the old fashioned way by eyeball and lined up target....sites still way high and not enough adjustment to compensate. If anyone has had this issue please let me know. thanks
Semper Fi

The iron sights sit about 2.5" above the bore, so there is a pronounced offset.  I always start with a mechanical zero (round base of front sight post flush and rear aperture centered) and get dialed in so that the POI is about 1.5" low at 25 yards and then finish off with a 50 yard zero.  Remember all elevation adjustments are done of the front sight.

Have you made any adjustments to the front sight?

Have not made any front  sight adjustment yet as I was trying to get a red/green dot sight bore sighted. the Red dot is on a co witness mount on the receiver rail. The magpul back up rear sight does not adjust  for elevation so the front site would need to be adjusted to zero....

Bare with me here.  This may sound KrAzy.  
Why don't you take it to a range and shoot / sight in, it at 100 yards.  
458

Have you tried a boresight target like this one? At what distance are you trying to boresight it? This one is for 10 Meters. If anyone wants a full size copy, PM me your email address.

Thanks that would be great! I am using a Vortex StrikeFire Red/Green Dot with 30 mm ring/ high mount for flat top. This should give me an Absolute Co-Witness with Magpul BUIS on my M4 type AR. Thanks again.
Semper Fi

I unfortunately  Will not be able to live fire for several weeks and would like to at lest have it bore sighted to be able to put it on paper with BUIS and Red dot..It is not KrAzy and admittedly I would have said the same thing.
Thanks

Loadthis;

This worked perfect and I think you very much for the target and help,
All the Best

Semper Fi

In theory, or practice
458

In practice the target is designed to give a 25 meter zero. The target is placed at 10 meters and the optic is adjusted until the bore laser reaches the appropriate point on the target. In Capecods case his red dot was absolute cowitness so he would use the EOTech bore sight point.

Capecodcowboy:  

Hit the range and AFTER I had bore sighted weapon all I needed was 4 rds to be dead on at 100 yrds. 4 clicks total. 3 e up, 1 w right. I really like being so close with a minimum amount of ammo expended! Laser bore sight, good rest and a great target made it easy.
Thanks again