EMI or Hevi-Shot did not tell the truth about most of the ammo that they made. I am pretty sure when Hevi-13 shot first came out it was close to being 13g/cc shot and then it turned into 12g/cc shot.
When EMI started selling Hevi-Metal loads they said it was Steel shot mixed with smaller Hevi-Shot. At that time everybody thought "Hevi-Shot" was 12g/cc shot that was 10% denser than lead. The smaller pellets in the Hevi-Metal loads was a tungsten blend that was not as dense as the "Hevi-Shot" that had always been 12g/cc shot.
EMI could not have sold Hevi-Metal loads as cheap as they did if it was 12g/cc shot that was mixed in with the steel shot in the Hevi-Metal loads.
So without telling their customers EMI turned "Hevi-Shot" into a brand name when before that 12g/cc shot was the name for 12g/cc shot.
HM-Back-Panel by https://www.flickr.com/photos/156463377@N08/, on Flickr
In the above advertisement EMI called the shot that was in the Hevi-Metal loads "Hevi-Shot". Up until that time nobody knew that there was shot being made called "Hevi-Shot" that was not 12g/cc shot. So EMI was letting people think that there was 12g/cc shot pellets in the Hevi-Metal ammo when there wasn't any
It looks to me like if you want EMI ammo that is 12g/cc shot it will cost about $6.00 to $10.00 per shell. The EMI "Hevi-Metal Longer Range" ammo is just steel shot with some Bismuth shot mixed in with the steel shot.
