The lower 1/3 cowitness was mandatory when the service rifle pattern with fixed front sight is used.
BUT - with free floats with 3 Gun style, no front sight is necessary. In fact, the civilian market is about 40 years ahead of military in that regard, hunting rifles dropped front sights in the 1970s when scopes proved reliable.
In the military, redundancy and extremely conservative standards retain the front sight on combat weapons because red dots can still be damaged due to impact by bullets or the user banging it around. Even with the advances of unbreakable glass for cell phones, nobody is willing to do the same for red dots - and the military hasn't picked up that requirement (which it could, but the offset would be even higher prices to make up for the lack of repeat sales. ) Nobody said the military can continue to make things more expensive in the face of a major downsizing.
If anything, the 3 Gun response has been to mount an alternate optic out of the primary sight plane. Much the same as NASCAR mounting a spare electronic ignition on the dash for the driver to enable in the race. A $300 part isn't allowed to lose you thousands of dollars by dropping you even one place. Again, it's an extremely redundant and conservative environment.
For a weekend or seasonal hunting rifle, do we need cowitness, or even iron sights at all on the AR? Again, the hunting rifle users abandoned the concept 40 years ago.
I'm installing a free float and taking off the front sight. Dead weight for a hunting rifle, and I prefer red dots anyway, as I have been shooting one since the 1970's. I expect to trim about a pound and a half doing it. The front sight is the heaviest item on the barrel and its loss makes a significant difference in reducing the muzzle heavy perception.
It's also noted the average soldier in the box keeps his BUIS either in his pack or under the bunk. Dead weight on the rifle may not sound like much, but he's required to hump up to 80 pounds on patrol, and that's when he focuses on every ounce he can to eliminate the weight.
Search the net, cowitness is passing away because fewer and fewer are buying AR's with fixed front sights. That was a '90s deployment kind of thing for a arbitrary military issue gun, and what we see now is that the AR is going thru it's streamlining phase post war now, just the same as the old milsurps getting cut down for hunting use.
Hopefully the results will be more appealing in terms of style.
