About 15 years or so ago I had a friend complain the 180 I interlocks I loaded for him were blowing up on game. I'd had good luck with that bullet for years so I looked into it. We glued an older one and a newer one to a board and belt sanded them about in half. The older lot had a thicker jacket and a heavy interlock ring and the newer one had a thin jacket and a barely noticeable interlock ring in a different place.
I called Hornady and finally got through to a tech that told me the engineers change them around all the time trying to make them more accurate. I lost a bit of faith in a bullet I'd used for years after that. I used to use interlocks all the time and loaded them for friends that didn't want to spend much.
I believe that's the stink I referenced above.
Probably, I wasn't the only one who noticed it. I think I figured it out around the mid 2000s maybe 2004 or so.
