I am partial to S&B, USO, Night Force, or Bushnell Tactical Elite. I routinely switch my scope out on my 50. Right now I have my Bushnell on it. I only currently own the S&B and the Bushnell, but just recently traded my NF. All of these are great choices for a 50 and hold up well to the awkward recoil of the 50 with a muzzle brake. I shoot a Bushmaster BA50. Post up some pics, I love the Windrunner, it is a great rifle. Enjoy, they are an addiction.