I have an elite 3200 1.5x-4.5x-32mm on my .375H&H mag and it has performed flawlessly. Still, a .50BMG is a lot of gun, especially with the brake.
I know many users of the .50BMG use Nightforce NXS scopes in their competition. I own one in a 5.5x-22x-56mm Illuminated, and it is one heck of a scope - ALL the way around. Still, at well over $1,000, it should be!
Zachary