I've got a Vanguard in .257Wby. It's not a MOA model, but it IS MOA for 3-shots with most loads.
It "likes" the Speer and Sierra bullets. Less so, the Hornady. Noslers Ballistic Tips are all the Nosler's I've shot through it, and it's accurate with them, but they perform poorly on deer at the ranges I've used them (under 150yds).
My only caveat against the Weatherby cartridges is the cost of factory ammo. If you don't reload, they're expensive to feed. The cheapest factory ammo I've seen is the Weatherby 100gr Softpoint (Hornady 100gr ptspt interlok) at Cabelas for ~$38.00 +tax = $40.00.
I reload, and form my brass from OFB 7mmRemMag that I pick up at a public range. I also use some surplus powder I bought several years ago at $5.00/lb. I also have .25 cal bullets that I've had on hand for over 20yrs for two .257Roberts I feed.
I think you'll like the .257wby. It's everything you've heard about it. But, I'd want a larger dia. bullet if you're consistently going after elk. Just a personal confidence thing.........