Simple question from a non-technical type: If the reading provided by the gauge depends on the dimensions of the metal, then how could a single strain gauge provide an accurate reading anywhere other than where it's placed? Assuming it's reading pressure in the chamber, there would not be any way to tell the pressure farther down the barrel, where the dimensions of the metal change significantly . . . would there? As I understand, that's why Bell used several strain gauges at various positions on the barrel. His tests were made in an effort to determine whether the peak pressure really does vary significantly between black and smokeless, and between fast-burning and slow-burning smokeless powders. From his results--and I think also from the earlier Dupont tests--it does not appear that there is much variation at all in the location of the peak pressure (always in the chamber), although there is some in how quickly the pressure drops.
