Well I guess I need to clarify a few things.

There were no cracks in this receiver prior to yesterday as I have been careful to watch for cracks given this was an Eddystone rifle. I fired a lot of rounds yesterday evening and barrel got really hot. Hot enough that I became concerned about crack forming from stress due to expansion so I stripped it down and lo & behold I found a light crack running back from edge of receiver. It was very light so I ground area to see if there was depth to crack and there was so gave whack with hammer and the crack enlarged. This tells me the metal is too brittle in this area.

I figured I would remove the barrel since I considered the receiver 'bad' at that point. I tried a number of different barrel jigs I have to remove the barrel. Nothing worked. Finally put a pipe wrench on barrel and you can see the result. I guess I didn't use the right tool since the barrel is still on. I was too lazy to setup my lathe to cut relief. This was a 'kick around' rifle so I don't really care and figured I might learn something by doing a little experimentation.

Anyway, I wouldn't call the metal soft by any means. I would call it tough. Nickle steel is tough and tends to stretch under high pressure rather than fracture. I have had some '98 mausers that were soft and there is a difference. However, in this case while the overall receiver is tough I suspect there are brittle areas.

While it may be true that Win, Rem and Eddy all used the same steel supplier, the case hardening treatment was done after receivers were fabricated so I suspect Eddystone may have had lower quality control for this process and likely overheated the thinner sections of the receiver which is where the cracks are known to form.

What did I learn: Eddystones receivers do crack, Eddystone receivers are impressively tough, Eddystone barrels are put on very tight, I don't understand the metallurgical reason Eddystones crack, if I buy another enfield it will be a winchester and remington.