Here is my dilemma:

I understand that the standard military zero for the M16A1 is 250 meters and 300 for the A2 and M4s.

I recently got some training that the zero for LE weapons should be 100 yards. That is because LE should not (generally) be making shots past 100 yards for various legal, liability and common sense reasons. The difference in point of impact and point of aim for weapons zeroed at 100 yards is 2 1/4" at point blank ranges (standard offset aim for most CQB weapons), to pretty much point of aim-point of impact from 25-100 yards (maybe an inch or so deviation).

My coworker, who is critiquing my training syllabus, disagrees with the concept of 100 yard zero. He thinks we should use and teach the military zero, which I think is far to imprecise for shots under 100 yards. My personal feeling is that it would alter the point of impact by several inches, and cause an unacceptable loss of accuracy.

Any opinions on this? Links to ballistic data on this subject?

Your bud is indeed correct, and is just so happens, that you are also correct if you zero at 25.  The balistic arc of the military zero range also crosses the line of sight at about 25 meters.  Ergo, it crosses the sight line at 25 meters on the way up, and drops back down to be dead on at the line of sight at the military zero range.

Pretty cool eh?  Set perfect zero for 100, and neither are correct.

If extreme accuracy is needed, why are you using iron sights?  Most can't shoot to the effective point blank range of the .223 with irons properly anyway.

[img]http://home.earthlink.net/~thegardenweasel/btgt.jpg[/img]
=P

Rather than try and remember this stuff, which I apparently am not that good at, look here:

[URL]http://communities.msn.com/TheMarylandAR15ShootersSite&naventryid=120[/URL]