Do you recall what book that was? I've seen one grain per CALIBER recommended as a starting or practice load, but never one per grain of bullet weight.
The only book of his I've read is one of his black powder "guides" that featured a lot of general ML info plus loads for most of the guns on the market at that time. He was pretty clear about the diminishing returns of heavy charges. The charges listed in the data section were all in the manufacturers' specs.
I do remember an old article by G. C. Nonte about taking some Navy Arms rifles to Africa and using some beefy charges under some really heavy conicals in .58 caliber, I believe. That was in an old Gun Digest, I think.
At any rate, one more time, the tests/demonstrations were illustrations using soft metal pipes, not gun barrels, to show what could happen with something like a improperly seated bullet. He was, as I recall, concerned that due to the relatively low pressure of BP, some people weren't treating it with the proper caution.
If, as you say he used to use charges equal the weight of the bullets he was shooting, maybe he gave himself a good scare.
