Sorry if this is a re-post, I tried to use the search function, but I don't have that privilege.
I guess it is all right for $15. I saw some threads on the 500 S&W damaging the rings because of a lack of support. That is one barrel I want to have fitted along with a 30-06 and a 20ga USH. I was placing an order for a magazine extension, so I went ahead and ordered a few of these. It looks to be somewhat robust, although the cross slots could be deeper IMHO. You can also see how the base allows you to use .22 rings as well as traditional Weaver style.