I don't remember what primers you are using, but I have a theory. It may be crap, but here it is. When I was reloading 22 Hornet, I read a lot about using very light primers, because the primer ignition could unseat the bullet and cause accuracy issues. Remington 6 1/2 primers were recommended. Some people used small pistol primers. Others would add a bit of a crimp. Since these cases are even smaller than 22 Hornet cases, my question/theory is what are the lightest ignition small pistol primers and would those light primers help?