Many guns can be damaged by dry firing, but not an A H Fox.
In the article "Why Should I Buy A Fox Gun?", in Volume 11, issue 1 of DGJ years ago, Tom Kidd wrote (in quoting Fox literature), that it will in no way damage a Fox gun to dry fire it, because of the way the hammer is designed and the way it meets the rear of the standing breech. As I recall it was described as having a substantial boss for the hammer to meet, not allowing the rear of the firing pin itself to ever contact the steel around the firing pin hole, preventing any possibility of "mushrooming" the steel around the hole as is seen on so many other old doubles.
