Funny you should mention rolling blocks, because my son picked up a number 4 in the nearly obsolete 32 Rim fire (OK, Obsolete), I saw the articles and web info on shooting it as a 32 RF, but that was a PITA too. I have beefed up the Screws and re-chambered it in 32 S&W Long, which may be obsolete too, but my local gun store had four choices of ammo for that chambering.
I think in general the percentage of 264 still used for game is as high as most cartridges, like I said in the beginning, some of the best Western big game hunters I know won't leave home without theirs.
