In retrospect it would have been better to utilize conformal pressure transducers as the frequency response would have been better. The same pressure transducer was used in both test barrels for each test series.
We also tested SMc proprietary reflective coatings for brass case inside surfaces. These coatings have been shown to provide an increase in velocity in straight walled cases such as the 45-70 of about 8 % but up to this time we have had no pressure data. We tested them in 6x70mm Norma cases. This is a very long slender rimmed case, as shown in figure 3; designed for European drilling (2 side by side shotgun barrels with a rifle barrel underneath) applications, great for hare, roe deer, and such small game. Briefly those tests gave a 2.5% increase in velocity and a 10% increase in peak pressure using Norma's factory load; 30 gr. VihtaVuori N-160 and 90 gr. Nosler Ballistic Tip. No attempt was made to develop a better load for coated cases as time was too short and besides I just had to go moose hunting.
A note here; 12-14 hour days, seven days a week in the test lab are too much for this 70 year old body (and mind)!
The Test Setup
Cases used were all Norma supplied.
404 Jeffery cases were shipped to Buffalo Arms Inc where the case
walls were thinned from about .023" to a very consistent .010". They
were then shortened and rough formed to the SMc configuration, fire
formed and necks trimmed to length and thickness. The 6mm Rem cases
were fire formed and neck turned to match the slightly tight-necked
chamber.