I think the Barnes is worth a try. An all copper bullet is a different animal than a lead core bullet. The retained weight will be higher than the jacketed bullet, thus during the impact will act like a heavier bullet than the 140g. For the distances your going to be shooting at elk any sacrifice in bc's will be minimal.
I have experience with the Swift Scirocco 130g out of a 6.5-06 on elk. Last season my son shot a big cow at 375yrds through the big bone in both shoulders and took out the front of the lungs. We recovered the bullet in the far shoulder and it retained 82% of it's weight. The bc's on this bullet are fairly impressive. Worth a look in my opinion as well.
Good luck,
Steve