This website might contain the answers to your questions.
Thanks, Meia. I do know of the site 
calibre length duh not bigger better dah.
larger round longer range better cpi comparison.
5.56mm is too small for comparative as windage affects rounds at
that level
Baer, thanks bro but it was supposed to be more food for thot.
Guess I could have worded in better duh.
I do own an Overwatch 24" and shoot the 6.5 Grendel for precision
rifle every month. Radford Arsenal (Alexander Arms) is here in VA
where I am.
If you guys are passing through, you're welcome to test it
anytimw.
On a side note, Meia, I know some folks who are building the 6.5
Grendel on a Mini 30 platform with a carbon barrel.