On Quickload, it (AA7) appears to do very good for the Rowland. I have heard that Longshot was a very good Rowland powder and I have no experience with the round. I anticipate trying it
I have some .460 rounds loaded, but they are just to establish a burn-rate baseline and get case capacity, which will help with future development. QL is a good development tool if proper parameters are entered, but the proof is in the pudding....
The Rowland case will theoretically have the same capacity with a bullet seated that a Super does, and AA7 has done well at about 24.5 Kpsi in that round, a load with the LFN GC having a 4 fps SD. My thoughts on the Rowland max pressure is the same as yours, around 34 Kpsi, and at that pressure and OAL I'm able to use with the MBC Pinbusters, 1200 fps is doable with AA7, but don't know if it is going to get squirrelly on me as I creep the pressure up. I could work on the leade and get 1.26" OAL out of the round, but I'm gonna save that for later.
I can seat the MBW LFN GC out to 1.25" without getting into the rifling, but I have to hold it to 1.23" so a loaded round will clear the ejection port, the meplat is so large. Feeding is not an issue in my Super, and so far the Rowland will hand-cycle them. I'll see what happens when I fire it. If it works, it will be my preferred bullet.
You seem to be comfortable with Longshot, I may pick a pound up while wandering around this weekend.
