I'm looking into some loads for a 9.3x57 and I'm wanting to be able to use IMR 4320 as that is my favorite rifle powder and works in almost every rifle I own with excellent results. I FINALLY found some data for that round and that powder. It was originally posted on an Italian gun forum and then reposted on Gunboards. Not an ideal source for reload data, but it's all I got.
232 grs IMR-4320 44,0 (min.) - 49,5 (MAX)
258 grs IMR-4320 39,0 (min.) - 44,5 (MAX)
The bullets I'm wanting to use are 270gr. Given that there is only a 12gr difference, would I be safe to assume that a starting load of 39.0gr is safe to use?