In a recent thread I had reported on cracking brass after being converted from 30-06 to 7.63x54 Argentine Mauser 25 years ago and shooting them recently. My question is, what would be proper guidelines for when converted brass needs to be annealed. And does it need to be annealed before the conversion or after, or both. In the above listed conversion, the brass was never annealed during the process. But a substantial portion of the old 30-06 brass was cut off (maybe 0.4" of it) during the conversion to Argentine Mauser brass. On the other hand, I have converted many 6.5x55 Swedish Mauser brass to 7.5x54 MAS which takes minimal trimming and have never annealed them or had any trouble with them cracking. So, is the key to needing annealing is how much of the original case was trimmed off? I have converted many 30-30 cases to 32-40 also without trimming and have always had good luck with them.