Well, that's too far for a MPBR zero, so you'll need to compensate for drop somehow. If speed is of the essence and 500 is the limit, a reticle works really well in my experience. What I'd do is, range a number of objects up the lane you are watching in hopes that you can skip the ranging step. Flags would be even better. But for me personally, 500 is not a quick shot regardless... I wouldn't go into this expecting quick 500-yarders, myself.
Somewhere out there in the 400,500 yard range is where you'll really start to see a benefit from higher-BC bullets as well. Without getting TOO esoteric, the 200-gn Accubond would be a good one. If you end up wanting to go further you'll find yourself sliding down a slippery slope...
