A year ago, a friend of mine was given a 22.250 by an uncle who was on his last legs, sadly, by the time the variation was done, his uncle passed away, so any information regarding reloading data etc, died with him, the rifle shot well with factory ammo, so he used the rifle but kept the cases until he got some dies, after a bit of fiddling and experimentation, he found a good recipe.
Roll forward to several months, he called me over as there was something wrong, l duly trundled over to find out what the problem was, he showed me the fired cases and the ones he'd sized, there was a marked difference between the two, l checked the dies, case length, then after a few minutes of head scratching, it hit me what the problems was, l fired his laptop up and confirmed my thoughts, the rifles was chambered as a 22.250AI, he ordered some dies and we knocked some loads up and tried them, not bad but a bit more tinkering found a decent accurate load, but none were as good as the loads made with the standard dies, after more jiggery pokery, we could not get the rifle to shoot any better, so now, he's sticking to loading with the standard dies.

Strange eh?