I have hunted elk for almost 1/2 a century and I don't know how many I have killed. What ever that number is, if you multiply it by about 4 or 5 is the number I have seen killed by friends and clients I have hunted with and guided.
7MM Mag is one of the more popular cartridges for elk hunting. So I do have some knowledge as to what works well and what doesn't.
If the words "elk" and 7MM Mag are together, I say without any hesitation use a 150 to 175 grain bullet and NOTHING that doesn't weigh at least 60% of it's fired weight when it STOPS!
Use NOTHING that comes apart more then 40%.
Barnes X, Nosler Partitions, anything bonded from any company, and Swift.
If you ignore everything else you will not be one of those people that has a report that is so-so or poor. If you use something else you may have a good report and you may not, but if you use one of these I recommend you will not have a bad report!
There are some other bullets that fall into the "good elk bullet list", but if you don't live in "elk land", and you are going to spend time and money to hunt them, do yourself a favor and take the advice I just gave. You will not be sorry.
A recap:
Any bonded bullet from any company of 150 grains or more.
Nosler Partitions of 150 grains or more.
Barnes X bullets of 150 grains or more.
Swift bullets of 150 grains or more.