Interesting ...

I have a 1963 High Standard Trophy Supramatic that was used by the Ft. Benning AMU for several years. The shooter sold it to me back in the late 70s. He put 30k through it and used Hoppe's on it after every match. I've probably put another 10-15k through it since I bought it. About 15 years ago I put it in a machine rest and 25-yard groups were all in the X-ring on a standard 25-yard slow-fire target.

I don't think I am going to get too worried about what Hoppe's Elite does to my 15-22's chamber. I'd love to see the results of actual hardness tests to substantiate that theory that Hoppe's softens metal.