Well, today was nothing if not instructional. Started off with a lovely day at the beach till I went to chamber a round.
Attachment 203839
As you can see from the following photo my issue is clear.
Attachment 203840
Why did I did not see this I don’t know. My initial dummy round, unmarked, looked and chambered fine but pretty much all the rest, bar one, have varying degrees of of donut syndrome. On closer inspection even my initial dummy round shows signs of swelling on the neck, clearly showing the bullet impression and looking back at the previous photo of the completed rounds, the fault is plainly visible.
Obviously the necks are way too tight and what I had thought was minimal pressure to seat them was totally incorrect. The only indication I probably had at the time was that I had to hold the bullet on top of the case as it went up into the die and thought that odd but dismissed my concerns.
So, a number of things going through my mind but will just stop thinking now and absorb some feedback if you all wouldn’t mind.