As I remember posting several times earlier, Remington ammunition catalogs from the 1930s and later stated that .38/44 loads were safe for use in ANY .38 Special revolver in good condition, not just HDs and ODMs. The only warning concerned greater recoil in lighter guns. And the .38/44 was loaded to a substantially greater peak chamber pressure than any of today's +P factory loads.

One major reason for the SAAMI chamber pressure changes in the early 1970s was that the Piezoelectric pressure measurement gauges were coming into use at that time, and produced far more precise and accurate data than the old standard CUP method, which is extremely crude by comparison, and not comparable to piezo gauge measurements. I doubt that any ammunition manufacturer on earth uses the CUP method today. The rule of thumb is to add 15% to 25% to the CUP to get an approximation of the peak chamber pressure in pounds per square inch.

I know lots about the USAF Model 15s, and they did not blow up or wear out, even with the more powerful PGU-12/B loads. The real problem was quite limited, and involved some incidents of airmen doubling powder charges in the M41 cartridge, which did damage the M15s when fired. The M41 bullet was not crimped too tightly, and was fairly easily removed. The PGU-12/B cartridge had a much higher bullet pull specification, and its bullet was nearly impossible to remove, so powder charges could not be doubled. It was the only handgun cartridge made at Lake City AAP, specifically for the USAF during the Vietnam period.