I have a bushnell trophy on my RB right now, a 2-6x. I have it mounted forward, so the glass is in front of the ports. The outside of the front bell gets leading, soot, and all kinds of crap on it, but the glass itself and scope function are just fine. I had to remove the front sight blade, the rear sight is unaffected how it is mounted.
I am using the taurus factory mount on mine - and you have to have a good set of rings for .454, no question.