i have purchased and mounted up the weaver style rings for use on a rem 7600 and a crossbow but havent been to the range yet. i like the idea of having something stronger than aluminum but wont rust like steel rings and mounts. i forget the name of the metal they used in making these but they are made for cva and also go under the name alumisteel.if you get them from the big stores like bass pro- -cabelas under the durasight name they cost more than double. they seem to be a copy of the warne type rings.they come with grade 8 torx screws so it seems like a good deal. http://www.grafs.com/muzzleloading/3443