People use .223's and .22-250's for bison culls all the time and elephant poachers use AK's in 7.62 regularly. That sure as hell doesn't mean that those are good hunting rounds to use for those animals in sporting conditions. My vote would be a resounding hell no. Elk are tough as nails and unless you're planning on only making head shots on animals that are calmly feeding or bedded at less than 100 yards you're odds of wounding and losing your quarry are too high. You have a responsibility to the animals that you hunt to kill them quickly and efficiently. If you have bigger calibers then use one. I don't use my .270 when I griz hunt, and I don't think you should use a little 6mm to hunt elk.

AK Jeff