My recently acquired #1mk3 came with a box of 80 reloads by the PO. Great deal. The 8th round fired resulted in a case head separation. The cartridges were bright and clean and came in a new plastic box with the load info written on top. Even though I have known about the frailty of 303 brass for 50 years, I neglected to check. Sure enough, there is almost a visible crack at the usual place. This is the 3rd separation I have had in my life shooting Enfields and have experienced no ill effect to me or the rifle in either. Don't know why.