My ARs all have XS Rear Apertures, where both apertures are on the SAME PLANE and ZERO in on the SAME POINT OF IMPACT  

Does the XS same plane sight change the procedure for the Improved Battlesight Zero (where you set the rear sight to bottom out at 8/3-2 clicks (new 200 meter setting))?

Does a same plane sight have any effect on the "Improved Battlesight Zero for the M4 Carbine and M16A2 Rifle"?

What changes, if any, need to be made?

Up front I would say no, but I am not for sure.

I would assume that everything stays the same except that you lose the ability to change elevation by flipping the aperture.  You should still probably be able to retain having the rear sight bottom out at 8/3 - 2 clicks.

Quoted: My ARs all have XS Rear Apertures, where both apertures are on the SAME PLANE and ZERO in on the SAME POINT OF IMPACT   Does the XS same plane sight change the procedure for the Improved Battlesight Zero (where you set the rear sight to bottom out at 8/3-2 clicks (new 200 meter setting))? Does a same plane sight have any effect on the "Improved Battlesight Zero for the M4 Carbine and M16A2 Rifle"? What changes, if any, need to be made?

The MDAR15 site has the answers you are looking for.  
Edit fur spelling

First, the IBSZ is to zero the sights at 50 yards for the flattest usable trajectory.  Period.  End of story.  Aint got jack shit to do with what type of sight you use.  Aint go jack shit to do with elevation marks on the rear sight.  The instructions about setting the sight to bottom out at 8/3-2 or 6/3-4 only apply if you are using an A2 style rear sight and want the elevation markings to be accurate.  

About your question, apply a little thought here.  As you already know and have already stated, the only difference between your sight and a standard A2 sight is the aperture.  With that in mind, what difference could there be except the obvious one that the POI doesn't change when you flip the aperture?  

Hoplophile,
I've always simply set the rear all the way down (not -2 clicks below etc.) and zeroed my XS same plane sight to hit point of aim = point of impact at 50 yds. I always understood that this was a fine battlesight zero. I read this IBSZ stuff and thought that there was more to this than what I already do. I'm trying to understand its purpose.

Quoted: Hoplophile, I've always simply set the rear all the way down (not -2 clicks below etc.) and zeroed my XS same plane sight to hit point of aim = point of impact at 50 yds. I always understood that this was a fine battlesight zero. I read this IBSZ stuff and thought that there was more to this than what I already do. I'm trying to understand its purpose.

There's no magic to it, and the way you've been doing it is fine.  The whole 8/3-2 thing makes it so that the range markings on the wheel will be accurate when using the aperture that the sights were zeroed with.  Since the same-plane aperture has them at the same level the range marks will work for both apertures.  If you don't care about the range marks then there's no reason to bother with all the -1 stuff.  Just zero the sights at 50 yards and press on.

I'd like to sight my BM XM15 E2S  for IBZ as described on the MDAR15 site.
However my Craftsmen 1/16" Ball End Hex tool is not turning/loosening the screw
(Step 3 below). Do I have the wrong tool or does it take firmer torque to loosen? I don't want to over-torque & cause damage.
TIA!


3. Using a 1/16" Allen wrench loosen the screw (under the revealed hole) in the sight wheel 3 full turns. Leave the wrench in the screw.

I couldn't get mine to break free either, on my Bushy removable carry handle.  I bent many allen wrenches trying.  Eventually I became convinced that I should just quit before I broke or stripped something.

Quoted: I couldn't get mine to break free either, on my Bushy removable carry handle.  I bent many allen wrenches trying.  Eventually I became convinced that I should just quit before I broke or stripped something.

Same here, tried on my RRA removable carry handle. Instead I just clicked the elevation all the way down and zeroed. Adjusted the front sight post 2 clicks. My local range only goes out to 65yrds.

If you don't care about the range marks then there's no reason to bother with all the -1 stuff. Just zero the sights at 50 yards and press on.

If you don't want to bother with all the -2 stuff, just zero at 36yds with the small aperture set to 8/3.  It's the same trajectory as the IBZ, but done at an oddball distance.

Don't forget to hard zero at 200m if you ever get the chance.