I've never seen a 6.5 anything used on elk, that I can recall. Strange. I've seen smaller (243, 6mm, 257 Roberts) and bigger (270, 280, 7RM, 30-06, various 30 cal magnums, etc.). What I noticed is that the animals all died about the same when shot well, and went a ways when they weren't. I have and hunt with folks that have a "shoot until it doesn't get up" rule. Shooting and then admiring the shot isn't allowed.
The most dramatic kills I've seen where the CNS wasn't a factor were from a 257 Roberts and 100gr Partitions at 250 Savage speed from just over 100 yards, a 300 SAUM shooting 190 Bergers at 70-80yds, and a 300 RUM at just over 200 using 180gr Sciroccos. All broadside, and all bang-flop. It really is the Indian, and not so much the arrow, I think. Elk don't want to die, but they succumb fast when hit in the right spot.
