A friend of mine who is a retired Marine LTC working at Camp Lejune and a Gunsite Academy devotee sent me this link a few months ago, I finally got a chance to read and digest it and it got me thinking...

http://robarguns.com/blog/2013/11/24/battle-sight-zero-bzo-who-has-it-right/

Being I hade almost 22 years of Army marksmanship dogma I was exposed to, even after 6+ years I am still trying to "unlearn" certain habits and reevaluate how I look at this kind of stuff. I realize that the Army trains people en masse and what they teach isn't necessarily the best method for a certain soldier, per se, but will generally allow a team of soldiers to accomplish their mission.  So while how they train troops may bring some weaker marksman up in ability to engage targets (and remember a "marksman" in the Army "qualified" with their rifle only has to hit 24 of 40 pop up targets), I feel it may also hold some soldiers who may be better natural shooters back.

My first eye opener was attending an Appleseed event and learning a sling was for more than just slinging your rifle over your shoulder in the chow line...and then that I could indeed hit a target at 500 yards, "the riflemans quarter mike", repeatedly despite being well past my former "maximum effective range" distance.  After reading the article I have to kind of agree with the 50/200 zero for the reasons outlined on the page.  As a civvy I would be really hard pressed to have a reason to engage anything past 200 meters and with my eyesight getting worse as the Years go by its harder to pick out targets at that range.   

Big thing I didn't really realize was that the Corp and the Army trained on different units of measure, yards vs. meters.   

The article also verified something that I had thought for a long time.. The Small aperture and the 0-200 rings were not centered on each other.....

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  The reason it is not on the same plane is that once the weapon has a 25m/300m BZO and the sight is moved from 8/3+1 back to 8/3, the large app is on a lower plane to be used as a 0-200m sight, hence the marking "0-200" on the app it's self.
 
  In theory, it being placed on the lower plane, there will be approx: 3"-4" difference in POA & POI at 100m-200m when using the 0-200 app rather than the nearly 6"-9" when using the small app when set at 8/3.

  Ideally, once again in theory, the elevation drum should also be set on 8/3-1 for all shooting under 300m. If the sight is set at 8/3-1, with the large app, there should be virtually no elevation diff between POA & POI. On 8/3-1, with the small app, it should be about 2"-3" high.
 
  The same applies to the detach carry handles w/ the 6/3 settings. For any shooting under 300M got to 6/3-1. (Also on those, there is an easy to see "Z" on the elevation drum for establishing BZO.)

ARMS used the same concept on their ARMS#40 rear sight assembly. While it has no elevation drum, the large app is for "0-350m" and on a much lower plane than the flat topped small app, which is their "500-600m" app. and significantly taller.