That pie chart gets drug out every time this topic gets brought up. I have 4 .223 AR's, and can confidently state that 3 of them throw brass into the red zone at 1 or 2 o'clock. The 4th one probably does too, but I can't remember. Two of them have been rebarreled several times and all are still running the original bolts. I like it that way. For those of us who shoot on a firing line with other shooters, my brass gets deposited in front of the firing line, not tossed into another shooter and his gear. It makes life easier when the brass call is given. I'm going to state that many, if not most, competitive service rifle AR15's behave the same way because I see most shooters up front looking for their brass with me. Every so often I get pelted with somebody's hot brass, but not that often (thank God).
I also have a 6.5 Grendel AR which is "perfectly" gassed according to that chart. I hate it. I'm scrambling around looking for brass behind the firing line that's been stepped on or tangled up in somebody's equipment., and that brass ain't cheap.