I have not been able to find any loads for the 38-40 that use IMR SR4759. I am wondering of Mr. Waters ever tried out this powder with the 38-40. His 'Pet Loads' book is on my birthday list, but until that happens, is there someone here that happens to have a copy of his pet loads for the 38-40 that could check to see if he tried SR 4759? I'd be curious as to what he says about that powder, if in fact he used in the 38-40.
Just in case you are wondering why I like 4759, in my trials and research thus far, it gives a pressure pretty much the same as FFg.