Dick, I now feel your pain. I've tried many things, but have not come up with anything. I have run into some of your posts on other forums on this subject during my search, so I know you have been trying to figure this out for quite a while.

What I am going to say you probably already know. The 1903 ordnance report dwells on the "experimental Springfield rifle" with barrel lengths of 24", 26", and 30", pitting them against the 1898 Magazine rifle (30"). They soon after settled on the 24". The 26" Krag likely became a mute point and not worthy of reporting the trial results as the trials were probably close together during the same fiscal year. There had to be a report somewhere, but possibly not where it can be found on the internet. Likely in some stuffy folder in a file long forgotten if not thrown out like you are suspecting.

I do many searches to pass time and find stuff I'm not looking for all the time, but still of some interest. So perhaps in my unorthodox methods I may bump into a reference to your subject of interest and will post it.