On my detachable handletop, the sight bottoms out at one click past the 6/3 mark.    

The local experts each claim something different--6/3-1, 6/3-2, etc--some say that it should bottom out AT the 6/3 mark.  One even claims that it does not matter.

I'd like for the absolute lowest rear sight setting to be zeroed for 100 yards (YARDS, not meters).  Is this recommended and, if so, how do I go about achieving this?

Thanks!

[url=http://groups.msn.com/TheMarylandAR15ShootersSite/zeroingmethods.msnw]try this[/url]
It's from the Maryland AR15 Shooters Site.
The Santose, or improved battlesight zero is probably the way to go.

I think you're supposed to bottom out at 6/3 and then do the military zero at 300 meters; that way the markings on the wheel are correct.  If you do the Santose method, you bottom out at 6/3  minus two clicks (or four clicks if you have fine adjustments), and then zero at 50 yards/200 meters, and the markings are still correct.

I'm not sure that this is correct, but it sounds right, and it should give you a 100 yard zero in addition to 50/200, and leave the markings on the elevation wheel correct.

For 100 yards, bottom out the rear sight and zero the rifle, using the front sight for elevation adjustments.  Then move to either 50 yards or 200 meters and zero the rifle again, using the *rear* sight for elevation adjustments.

To do the next part, it helps if you read the Santose zero instructions, since it describes how to do this better than I can.  Flip up the small aperture, and under it you'll see a tiny hole with an allen-head screw in it.  Loosen that screw a little bit, and you disconnect the top half of the elevation wheel (the part with the numbers) from the bottom half (the part that is attached to the rear sight and makes it go up and down).  Turn the top half until the 6/3 lines up with the mark on the rear sight, then back it up two clicks (or four clicks, if you have fine adjustments -- this is all in the Santose document).  Tighten the screw.

Make a witness mark on the wheel to denote your 50 yard/200 meter setting.  Santose doesn't do this because he bottoms out at 50/200.

This should give you 100 yards with the sight bottomed out, a mark for 50 yards/200 meters, and marks for 300/400/500/600 meters.

jafager

The Santose IBSZ is the way to go for an M4!