I've been following this thread since I went through this same thing last year.
I needed a new gun, been archery hunting for years, and wanted a non-magnum caliber. I grew up shooting a 7 mag, I still have the gun and love the caliber, I just wanted something that didn't kick as much. Recoil doesn't bother me but I wanted something I wouldn't feel as much after shooting on the bench. I was really wanting a 6.5x284 or 270. Even though that's what I wanted I found a good deal on a new Tikka 7mm Rem Mag and bought it. I put the Nikon 4-16 on it with the Sims recoil pad. Problem is, since I set it up, I've never fired it. All my hunting opportunities escaped so it's sitting in the safe...I hope to get it out this week and start shooting it finally.
As far as ammo goes, this is what my son has got me wanting to try. In fact he bought a couple boxes for my birthday so we'll see how it shoots. All I can tell you is that him and his buddy (long time guide) both swear by this ammo in their 257 Wby Mag.
https://www.midwayusa.com/product/6...-shock-x-bullet-boat-tail-lead-free-box-of-20