I hunted with a 7mm Mag for many years and formed some of my own opinions about it. 1st, it was a great long range cartridge, I made some really great shots with it. I shot a 160 grain Nosler partition with a MV of 3150 (I had a fast barrel) The partition did a good job of terminal performance without destroying a lot of meat. The cartridge worked well for deer size game. I did manage to finish off a near record book black bear with that gun and that was when I really started to question the caliber for large animals. The killing shot on that bear was from around 150 yards, entered behind the shoulder. I recovered the bullet, it never touched the rib cage on the off side. Not adequate penetration for my liking. On another bear hunt, I shot a beautiful big bear across a canyon at around 500 yards. I watched as the bear bit at his shoulder after the shot and then watched him roll several hundred yards down a very steep hill. I looked and looked for that bear and never even found a drop of blood and never found the bear.
Now back to the elk hunt. I like accubonds, but they aren't quite as tough as I would like. The front portion of the bullet tends to explode on impact in the smaller calibers. I witnessed this on an antelope this year with 180 NAB's out of my 300 ultra at 400 yards, 8 inch hole in the hide on entrance, and I recovered the bullet on the off side. Very dead antelope, but I would have questioned this performance on an elk also. The same results happened with a 243 and an 85 grain interbond, bullet blew up on the entrance and only did surface damage.
Back to the elk question. The 7mm with the accubond will kill the elk, but I would shy away from a direct shoulder shot and instead place the shot behind the shoulder for maximum tissue damage. Elk shoulder blades are fairly tough and can compromise some bullets integrity, which is why if I was picking a bullet for elk out of a 7mm, it would be in the 175 to 180 grain range for maximum penentration.
Now, after shooting a 7mm for many years, what did I replace it with? A 338 and I can tell you that there is nothing like hitting a big animal with a big caliber and watching it get hit with Thor's sledge hammer.