Well Jim . . . while headspace may not be the problem in all cases, apparently it is in at least SOME cases, and Thomas even provides a "finding out for myself" example:

"In the first case, the cause of the violent recoil was diagnosed as excessive headspace by a gunsmith. I confirmed the reasonableness of this diagnosis and suggested that the shooter should test it by preparing some cartridges with metal-foil discs stuck on their heads so as to fill the headspace. He did this and duly reported, 'I stuck two discs of foil on the ends of ten cartridges with a standard load. The gun shut comfortably. I shot off all these cartridges in five minutes. I did not notice the recoil at all, and shot without any discomfort. Your prescription was perfect.'" Of course we're talking the "sensation" of felt recoil, so I suppose it could have all been in the shooter's head, but there it is. Sometimes a "tinfoil hat" really works. smile