Dan;
Thank you for the information about Mr. Bell. He obviously appreciates the importance of calibration. I'll try to contact him.
Brad Millard runs the jbm site. He and I have swapped a few insights and reminiscences about Bob McCoy. Bob's premature passing was a real loss to the ballistics community.
Like yourself, I have seen some authors refer to an alleged naval test of BP that produced higher pressures than 86,000 psi. When contacted, one of those authors said he found the naval BP pressure info in Dr. Tenney L. Davis' book The Chemistry of Powder and Explosives. I got a copy of that book. It's very comprehensive and has a lot of information about BP chemistry. But I could not find any reference in it to BP pressures.
In the period before and after WW1, the military services were experimenting with many different propellants, some smokeless, and some based on BP. One kind of powder called brown powder was a BP based on, I recall. a coconut shell charcoal. It produced significantly more pressure than traditional black powder. Also, there were several nitrated semismokeless formulations which tended to generate very high pressures if improperly handled. Black powder is still in use as an igniter for artillery pieces, but I'd be moderately surprised to learn that straight BP was used for combat in naval guns after WW1.
Cheers,
Dick
