It makes sense (to me) that a cartridge would work because most are tapered, even if only slightly. I'd imagine finding one that's just the right size for the pipe and with just the right amount of taper would take a little tinkering. Of course you've got to cut it, and be willing to sacrifice a pipe too. I have a spent 5.56 NATO round and it's just a scoach on the small side for a Nording (the tenon), and that was the pipe I want to try it on. I think maybe the neck from a 30-06 would work.
I wish I could find an example of what I'm day-dreaming about here though; where someone actually had a pipe that they put a cartridge into to fix a bad joint. Google image searches so far haven't turned up anything. There are some videos that show how to make a proper one from scratch though, one's by J. Alan.