Daryl, I think that you're right on with your theory. I just received my Woodleigh loading manual and it states in the heading preceding the load data that loading below approx. 128 grs can create erratic ballistics and that this could lead to higher extreme spreads and sometimes hang fires and misfires. They also advise a filler to be used under 128 grs on any powder. I was using CCI rifle magnum primers while the manual called for Federal 215 primers. It may or may not make a difference but I need to take out all the variables that I can. Tomorrow I will head to Fin Fur & Feathers to get some Federal primers and a different powder. I have seen where a lot of people are using Alliant RE15,19 &22 with RE15 being used the most. I have a Lee factory crimper being made and that should help also. I used a pretty hard roll crimp on the last firings but I think the lee die will offer a better one.I have been reloading for over 40 years and have never seen necks do what these have. I've seen dents in the cartridge body but not the necks. I think your synopsis about the partial ignition along with the hang fire makes total sense.