Since we're making a book out of this thread, I thought I'd ad some pictures 'cause I hate a book without pitchers.

This little unit is how far consumer products have come. Oehler was the first to introduce a consumer level of pressure measurement device in his "Ballistics Lab" quite a while back as I recall. It was expensive (still is) and didn't keep up with the times IMO. The Pressure Trace system is based on laboratory grade strain gages and a common PC with software that takes the raw strain data and crunches it instantly to useable data by factoring the strain gage calibration offset, barrel measurements, etc.. The sample rate is very high (a lot faster than the Oehler) and can provide very good resolution of peak pressure, even in pistols and high intensity rifle cartridges.




Using one of the common singleshots (H&R and similar) provides for a constant diameter (not highly tapered like a sxs) at the chamber and reduces the chance of measurement error of the wall at the precise location of the strain gage. Strain gages rely on known E-modulus (Young's modulus/modulus of elasticity) which is very consistant for steels (another reason to instrument a steel barreled gun instead of a damascus gun (maybe))




This trace is of a WallyWorld Federal 16ga shell. Note the pressure. I don't believe every SAAMI compliant shell is SAAMI max pressure, quite the contrary.