According to the Hodgdon’s data IMR-4320 is only used in the larger 6MM cases like the 243 Win or the 6MM Remington . It’s a great powder in the 308 Winchester, and the 7,92, haven’t used it in the 243 as of it .
Your very welcome, no problem. Your are correct according to a older burn rate chart that I have, it right after Varget. But on a recent Hodgdon’s burn rate chart, 4320 isn’t even on there. Hopefully this will be of some use to you. https://www.6mmbr.com/6mmbr.html