Finch,
I use a .308 with fairly cheap bonded lead bullets, and will be upgrading these to yet a better/higher ballistic coefficient bullet next year hopefully after some summer shooting/testing. I like the lack of recoil with a 308 so feel very comfortable with this rifle without a suppressor... and from what I've read, with good bullets a 308 is good to go on elk to 425 yds and deer sized game to 650 yds. I don't really know from experience though, because everything I have ever shot (except targets) has been 300 yds or under.
I am not in the greatest of shape, but the entire packout was uphill and off trail (easier on the knees but slower). It would have taken me at least 2 full days to pack out this elk on my own, if my body held up. By the last load, stepping over logs that were knee high, felt almost like major obstacles. I am frequently much farther from roads while hunting than this elk was, but this is because I will typically ride or push my bicycle w/ trailer or more infrequently pull a pulk in up to several miles on a closed road. Then while hunting I am within a mile of these transportation aids that I stash on the closed road.
I guess when judging your own capabilities, for a big elk, consider it is like dropping 5 deer all at once and then dealing with that.