It is in the same class as the .30-06. The 8mm just never gained much popularity in the U.S., but it does have kind of a cult following. Remington did a production run on the caliber a few years back in the "Classic" CDL, and there are plenty of sporterized military rifles out there to be had. I wouldn't hesitate to use one for elk if I owned one.
Factory hunting ammunition isn't easily found in most stores, but thanks to the internet you can find it. I have an 8mm-06, throat was bad so it was reamed out before I bought it. I can't complain how it shoots but I've only used 175 grain bullets in it, and it has only killed paper.