No. I'm not confused. The Eddystone has a long and well earned reputation for cracking. Usually when the OEM barrel is removed. The Winchester and Remington don't seem to have this problem. The breakage does not seem to be confined to the M 1917. The P-14 are breaking too. However I have an ERA chambered to 340 Wby and have had no problem with it.
I have read a lot of stuff where the techniques of manufacture between Springfield and Enfield are switched. That hasn't anything to do with my Rockwell test.
thanx
BB