I posted this at another sight but no one answered so maybe you guys can help me.
When sighting in, I use a detachable carry handle, so my sight is the small aperature and -4.  My question is do the large and small aperatures have the same point of impact.  SOmeone mentioned that the large aperature shoots about 2 MOA lower then the small, but then why does the IBZ say to return to 300/600 when switching back to the large aperature for patroling?  Wouldnt that lower the point of impact even more.
I hope that I understand this correctly in that the -4 clicks means 4 clicks up, meaning raising the rear sight(clockwise) for the small aperature zero

I appreciate your help

No.



Because the large aperature isn't on the same plane (it's lower) as the small aperature. Raising the rear sight's elevation wheel cancells out the lower large aperature.

For patrolling under combat conditions, the "flat" on the elevation wheel can be verified by feel alone. Guess that's why it's used in conjunction with the large ap.



[url]http://www.ashleyoutdoors.com/news.html[/url] FAQ question #10

In summary:

POI using 6/3-4 with small aperature will equal
POI with 6/3 with large aperature.

Coulda swore at least two people replied to your earlier post.

The -4 means *minus* 4 clicks.

Does anybody know why the rear sight was designed this way?

So you can use the sight out to 300m without adjusting anything but flipping the aperature.

With a (nice 1-2MOA accurate) carbine (as opposed to a beat up and abused M16A2) I shoot Approx 4-5MOA with the big aperature so I would never have been able to figure out it was 2MOA lower.

I like my small aperature it lets me hit what I'm aiming at at longer than 100M.

That big aperature doen't seem to have a purpose outside of buildings.

So the -4 clicks means that you actually go PAST the 300/600 when dialing down.  This would be turning the dial counter-clockwise, not clockwise like the IBZ FAQ says at the Maryland site.

Im just so confused...argh!

To get full benefit from IBSZ you have to reset the range wheel.  To do so requires loosening the locking Allen screw and elevating the sight up 2 clicks (8/3 sight) or up 4 clicks (6/3 sight).  Lock the wheels together and then click the sight down until it bottoms out.  It'll be at 8/3 -2 or 6/3 -4.

As noted the 0-2 aperture is lower then the unmarked aperture.

The author of IBSZ has his Email posted in the instructions and sometimes drops in here.  No need to be confused, just read the instructions again and ask questions.  [;)]

-- Chuck