xausa, you wrote you would recommend it. But it looks as if you meant to write you would not recommend it.
I am a bit confused.

One thing we need to consider is the fact that I am loading a standard 8X57 not an 8X64 or an 8MM Mag. So my striking velocity is likely to be between 2300 FPS and 1700 fps. At that speed I wonder how much better the bullet would do compared to the higher velocity of the mags and the 8X64? My muzzle velocity is 400 to 500 FPS slower. In my experience the higher velocity flattens out the trajectory but is not usually a better killer on large animals. There are exceptions, but most of the super fast shells do not kill elk any better than those that shoot from 2500 to 2800 FPS. They make hits at longer range a bit easier but the killing effect is not better. In fact, if the bullet fails they magnums often do not kill as well. What say you?

I picked up 2 boxes of Speer 200 grain bullets too. I have yet to load them. But I bet they would work fine out to about 300 yards.

Do you (or anyone reading this) have any experience with the Hornady 170 SST or the Speer 200 grain 8MM bullets on game?

Most often American hunters kill whitetail deer. A bullet that works perfectly on a deer is no guarantee that it will do fine on elk, but a bullet that comes apart on a deer is never an elk bullet.

Here in Wyoming I like to hunt elk in the trees, but last year my wife and I found them out in the open planes and I had to make long shots. We used a 270 and a 308 last year and did fine.

But I am going back to the trees this year. I like that kind of hunting better. So I expect to make shots at 100 to 150 yards, and it is not at all unusual to make shots at 35 to 50 yards.

If I need to shoot a long way I can always use my 270, 30-06 or my 300 H&H. But I just like hunting them up close better.