Yes.....I hunted with a licensed guide out of Colorado once - he was on holiday in Wyoming and we had mutual friends. All he wanted in his 30-06 was 165gr Nosler Partitions. On the other hand, my Dad will load nothing but 180gr Nosler Partitions at about 2500fps for his 30-06. Several deer and 4 elk says he's not wrong. It's given him confidence to do the job. Where is your confidence? Load that in which you have confidence. If your buddy is an experienced big game hunter and is handy with a 30-06, he should not have a problem with your choice - what is he used to? Give him a load he can be confident in, and your choice should work just fine.
My last Wyoming elk dropped from a cast bullet out of a 32Winchester Special, but I don't make a habit of it. Put the bullet where it needs to go with enough behind it, and they will go down.
Regards,
Sweetwater