Good Morning, COBigJohn,
Seems as though everything hunting involves compromise. But I might be ahead of myself. Is your 7MM Rem Mag to be used for hunting or target shooting?
I know that this is a long range hunting forum. However, I've gotten the impression that many have long range hunted only in the abstract. Reality is a whole lot different. Moreover, long range can vary from hunter-to-hunter. For me, it's ~400 yards, and that's under perfect conditions.
Some 25 years ago I bought a Sako AV Classic in 7MM Rem Mag. I believe it's twisted at a ratio of 9.5:1. I do know that it'll shoot a whole lot farther than I'm capable. And it's a whole lot more accurate than I'm capable. Three shots touching each other at a hundred yards at about .25" is pretty darn good. And I reload for hunting, not target shooting.
From experience, a 160 grain Partition fired from my 7MM Rem Mag will kill huge bull elk dead as dead gets. All I gotta do is destroy a bull's oxygenating blood pumping apparatus, and he'll hit dirt.
My opinion is your 7MM Rem Mag will kill big game as dead as a .338 Lapua. In fact, big game used to die when they were shot with the 7x57, .30-30 Win, 6.5x55, .45/70 Gov't, the '06, and a whole lot of other similar cartridges. It ain't cartridge that kills big game. It's what bullets fired from them destroy that does.
I've seen well-put-up studly dudes flinch from bench shooting sporter weight .300 WM. I have an absolutely beautiful Belgian Bowning manufactured circa 1969 chambered for .338 Win Mag. I've fired it 3 times. That was over 30 years ago. I ain't fired her since. She's much too powerful for anything in North America. Maybe some day I'll get bored, put a scope on her, load some rounds for her, and send a few bullets down range.
IMO, right after a bad shooting rifle, flinching most negatively affects accuracy.
The compromise I ain't willing to make is weight. Lord knows, I've yelled words I didn't know I knew at my 10+ pound 7MM Rem Mag while climbing high ridges in Wyoming's Star Valley. After my second year of that torture, I went lightweight.
