One Scope, or Two?

[jamichau]

I'm a newbie to higher caliber rifles. I'd only owned a 10/22 with open sights until I recently purchased an MGI Hydra with which I can shoot 3 calibers: 5.56, 300 Blackout, and 6.5 Grendel. I would like to purchase one scope that I can use effectively with all three cartridges, meaning as useful at 200 yards as it is out to 800-1000. Is this unrealistic, or might I be able to purchase one that fits the bill? I'm interested in Vortex brand, but not necessarily committed to it. Thanks, in advance, for any advice.