[RKV]

6.5 Grendel, uses the same lower as the AR. "First unveiled in May 2003 at the Blackwater Training facility in NC, the 6.5 Grendel® out-shot the 7.62 NATO at range with half the recoil. Still supersonic at 1200 yards, the 6.5 Grendel® delivered superior external ballistics to the 7.62 NATO." http://www.alexanderarms.com/grendel.htm

[rickdylan]

The Grendel is certainly better than any sort of 223. Nonetheless when they say “super ballistics to the 7.62” they almost certainly mean superior to the 7.62 with the standard 149 gr bullets. Loading the 308 with 165 gr bullets fixes that and the 308 is still significantly bigger.