If it were me I'd use a 2X-7X.
Holding the cross hair where it needs to be is what is important.
A 16" hold-over when the target appears 4 times larger than with the naked eye is no different then a 16" hold-over when the target looks 16 time larger then with the naked eye.
The difference is how fast you can get on that target and make a good shot. And that difference is HUGE between a 2X or 4X compared to a 9X or 16X.
Higher magnification comes at the cost of a larger scope and less field of view. ( and more money too) Elk are big targets and don't need much magnification.
In the Marines we shot to 500 yards with iron sights, and when I was young (and had outstanding vision) I shot very well at the 500. In fact I shot very high scores, usually going between 235 and 247 of a possible 250 for the K.D Qualification.
Now that I am old I need a scope, but I have shot a very similar course of fire just 2 years ago using my AR-15 with a Weaver K-4 and I shot a 244. The scope doesn't make the target bigger at all. It only makes it look bigger. It also does nothing to make your hold steadier. Clear sharp images and a WIDE field of view do help, but magnification does not.
I think most men use more scope than they should, and if they tried something a bit smaller I am guessing they would be happier. That's my conclusion from not just my own tests, but from pretty constant feedback from my students. I ask them to try a rifle and use 2 different scopes, on moving courses of fire, with shots coming from 35 to 600 yards. So far only 3 out of I don't know how many (probably over 100) have said they liked the higher magnification for a running course. All the rest told me the course was easier with a low powdered scope.
If you are setting up for bench rest competition or for prairie dogs, having 9X or more is nice.
But for hunting anything from deer up, I have found that a lower magnification is better.
I have 3 rifles with 3X-9X scopes, and my 222 Remington which I like for prairie dogs has a 4X-12X
ALL my other scoped rifles have fixed 4X scopes or 2x-7X scopes. And the 2X-7Xs usually "live" on 2 or 3 power.
I killed my elk this year with an 8MM Mauser at about 200 yards with the scope set on 3X. I killed my deer with it set on 4X. Last years I killed an elk with a 270 WSM at 400 yards with the scope set on 2X. I used a Ruger 9.3X74R and the 8MM for my deer. The 9.3 was set at 2X.
I find it's a lot easier than when the target in a smaller field of view.
I have removed several 4X-12X and 3X-9X scopes from my rifles over the last 25 years or so, and sold them off, and replaced them with lower magnification scopes. I am very happy with the results.
You might try it and see. My guess is that you'll like it too.
