I've got a very good friend that has the Vortex Viper 6.5-20X with a 50mm front objective on his varmint AR rifle. For the money...I think it's an excellent scope. Whether it's a good choice for your new Weatherby....I don't know. On my custom .25-06...I have a NightForce 8-32x scope. I use all 32x when shooting prarie dogs at long range...800+ yards.
If the Vortex Viper fits your budget and needs...I'd highly recommend it. Good glass...nice turrets with repeatability...Two thumbs up.
I shoot a 257 Weatherby with a Burris Black Dimmond 4X16X50. I think they were made for eachother. Very happy with that combo. I had the target knobs installed at the factory. Burris is great to work with. Bill Maylor..