Hello, I am posting this for a friend of mine that isn't that computer savvy. He just purchased a M99 in 50bmg. He is looking for a scope for it. He kind of has a hard on for Leupold. What is a good size scope? I had done some looking for him and found a 4.5-15X50. He didn't think that a 15 power would be enough for this rifle. What are your guys thoughts? Knowing the guy, he will mostly use this to punch paper, and maybe the occasional plate. Thank you. Also, some good rings.