7.5x55 is the reason I'm rationing my Re-17 and looking for replacements. I have nearly 400 rounds of GP11, however, so not loading that one just now.
During the last shortage (remember that?) I acquired a jug of IMR-4320 to replace the then scarce Re-15 that was my go to in .300 Savage. Ironically, it's been discontinued, and I have been able to get Re-15 lately. But my remaining 4320 is doing good duty in a number of rounds, particularly 250-3000.
IMR-4955 Enduron is doing well for me in Re-22 applications, although it's a little faster. Ramshot Big Game seems about as close as I will come to Re-17, not the same, but it looks good in 7x57 and 8x57.
Alliant 4000-MR has been an enigma to me (can't run QuickLoad), but this morning I got some excellent results in 300 H&H. Hunter looks good there too, but I got better accuracy with the Alliant.
Right now the only test I have planned for StaBall is in .416 Rem Mag, and that will be after my next dental appointment to be sure my fillings are secure.