I'll have to consider them next year for my antelope hunt. Either the 6.5 or .284 bullets
It's a solid copper bullet, so they willl expand less violently and keep together better then a lead cored bullet in general, and since they also in general needs more resistance to expand reliably a lighter weight one at a higher speed is usually better.
And complete penetration on elk should'nt be a suprise.
And the last little bit of BC matters less then a quick clean kill.
monolithic copper bullets in general also are'nt ideal for really long range shots, as they will generally pin hole earlier then a more fagnible lead core bullet.