I'm not a metalurgist, heck I don't think I can even spell it, but, I would have to say that the high intensity heat of the powder gases released from the barrel/cylinder gap, would eventually temper the top strap to where any additional cutting ceased, just a thought. I shoot only 180gr. and larger bullets on top of 4227 and mine show flame cutting, but it has never gotten any worse. As Whit said, forcing cone erosion only became an issue with fast burning powders and lite bullets at Mach 10 speeds. Not at all what the round was designed/intended for. Coogs.