Welcome to the forum, thanks for your service, and congrats on the new 7mm STW.
But, one thing, it's not called an "STW magnum", it's just simply "7mm STW". Not a big deal at all, just trying to be helpful.
You should come join us over in the 7mm STW section of the forum.
7mm STW - Long Range Hunting Online Magazine
Post some rifle pics when you get a chance.
Accuracy is variable from gun to gun. My factory Remington Sendero SF 7mm STW will shoot 1 ragged hole with the right handloads in it.
Optimum load data is another thing that is individual per gun, I can give you some load data that might get you close, but as for final tweaking you'll have to do that. If you need any load data for Nosler, Berger, or Hornady bullets, let me know, as I have the manuals sitting on my loading bench.
As far as range goes....Well, I'd be willing to say you could easily kill whitetail deer ~1,200 with a really heavy high-BC bullet like the Berger 180. Elk, probably up to +/- 1,000 yards.
It's a pretty nasty caliber. I think you'll enjoy it.