When you reloaded the old AA hulls there was no hole in the middle of the crimp. I've tried many times to adjust my machine to load the HS hulls but still get a hole in the middle most of the time and the case sometime collapses at the bottom.
That makes sense. The HS hulls being a tapered hull have slightly less capacity than a straight walled hull of the same length so loading the exact same load will be a tad taller load column making the amount of plastic available for the crimp short leaving a hole in the middle. You should find the opposite issue going the other way. If you have a load that loads perfect in a tapered hull and try to use that in a straight walled hull, you SHOULD see a swirl in your crimp as there is too much plastic to crimp since the load column is slightly shorter. A faster powder to reduce the powder charge or a slightly smaller shot charge should eliminate the hole in the centre by shortening the load column.
