I once read an account by old time gun writer Jack O'connor, about a claw mounted scope that had lost its tight fit and became inaccurate and worthless. But the conclusion that he came to, "claw mounts are unreliable", is incorrect. Claw mounts are very precise, very elegant, and require many hours of training and very precise craftsmanship to fit and install correctly. Hobbyists and self trained amateur gunsmiths need not apply. As I understand it, the "claws" come from companies like EAW and Recknagel as "soft" untempered studs, and must be meticulously hand filed and fitted to tolerances that require a watchmaker's precision. Then they are heat treated. The heat treating ensures that the claws do not deform under recoil. Done properly, they are wonderful. Done poorly, they are horrible. I have several rifles that have been properly equipped with claw mounts. Love 'em.