Was talking to a friend the other day about receiver sights on long guns in general and Contender carbines in particular. He mentioned that he used a Williams WGRS without the aperature on his 12" 35 Rem to hunt and liked it alot. He said he didn't have any trouble with target acquisition and, like an aperature sight on a long gun, you view the entire target - the rear sight doesn't obscure the target below the bead or top of the post. I imagine a small diameter Firesight type bead would stand out well.