Now I'm seriously confused.
A temporary condition that a stout dose of technology will cure 
. There's only one pressure peak, after which pressure drops.
If refering to the chamber pressure, yes. We refer to that as peak chamber pressure. However, all areas of the barrel are unaware of that peak chamber pressure as they are sealed off from it by the wad. Only goes one direction after the peak, which is down.
Agree. You talk about "the decay in pressure" while also referring to "peak pressure at each location from chamber to muzzle".
A strain gauge at the middle of the barrel would never record the peak chamber pressure. At wad passage, it would record a peak pressure unique to the mid-barrel location and then a decay of pressure. It would see a peak pressure greatly lower than the peak chamber pressure. Those two concepts directly contradict each other.
Not quite. Peak, as an adjective, means highest--and there can be only one highest.
There is a peak pressure for each location in the barrel and each is different. The commonly used "peak pressure" is actually peak chamber pressure; which is the highest for the barrel. Everything else is lower.
Yes, but if you select a location other than the chamber and wish to know the peak pressure of that location you will not use peak chamber pressure. You also have contradictory statements about pressure measurements. You agree that the gauge only measures pressure where it's placed . . . but then you tell me it measures pressure all the way down the barrel. If it did that, then why did Bell use several strain gauges?
Evidentally he did not have a conversion of time to displacementand/or he wished to iron-clad sure of his data. And I thought we'd agreed previously that a strain gauge depends on the dimensions of the metal--which obviously change significantly from chamber to muzzle, which would make it impossible for a single gauge placed in the chamber to measure pressure at the muzzle, where the dimension of the metal is very different.
Nope. Note that I said that the pressure at any given time/displacement is basically uniform throughout the enclosed volume (disreguarding some small differences due to flow). Therefore, the chamber strain gauge (or, for that matter, a recording pressure gauge with a chamber tap) gives pressure of the enclosed volume vs time or displacement. The measurements of the metal are used to calibrate the strain gauge to produce accurate readings. Correlation of voltage to gas pressure depends on the metal strain which depends on the measurements/dimensions and the gas pressure. So, if I feed the computer the gauge characteristics for converting metal strain to voltage and the metal dimensions, I have a product of pressure. Waters are getting murkier and murkier . . .
