Whitworth and several others swear by the ultradot and he uses them on a lot bigger guns than the 480. I've been using the Millet sights for a while now and had no problems on 454's, 475's and my 500 Linebaugh. The Ultradot is built better than the millet so you won't have any problems with the 480 beating it up.

I won't be wronged. I won't be insulted. I won't be laid a-hand on. I don't do these things to other people, and I require the same from them. John Wayne-The Shootist