I don't know much, but will pass on what I've heard. The only VV 500-series powder that comes close is N-530. It's real-world burn rate is suppose to be about the same as 4895. In fact, I've substituted it for 4895 in my .223 & found it to work very well. This with a 65-grain bullet, heavy for a .22
But it is a dense powder; you can get a lot (by weight) in a case. Roy Darnell once remarked that he'd tried it in a .30 BR, and while he couldn't get the usual velocity, it was quite accurate. Well, the .30 BR generally uses faster powders than a PPC, and (relatively) lighter bullets, so if you're not a speed freak, 530 may prove interesting in a PPC.
I've always liked double-base powders. Their sweet spot is usually a little broader than single-base powders. But Rel-7 is a little too fast for a PPC, Reloader-10 proved a bust (so far), and I don't know of any others that aren't ball powders.
If you have an adequate supply, give N-530 a try & let us know.