Your neck tension is off. Are you FL sizing with an S die? Make sure your bushing is appropriately sized for your specific brass. You may also try annealing to help mitigate any brass spring back post sizing.
I agree with Sawtooth; your neck tension is the problem. That said, I have been using a LEE Factory Crimp Die with very good results shooting Hammer Hunter bullets. The crimp has made significant improvements in accuracy for 4 different rifles I have developed loads with. It is worth mentioning that I am not using the crimp die according to the Lee directions but am using a "partial' or less than "full" crimp as described by another fellow on the "Hammer time forum" - his screen name is "Butter Bean". I have been using .003-.004 neck tension with the Hammer Hunter bullets and tuning for optimum crimp, FWIW.
Redding is a reputable company, call them, review your process and if the issue is on their end they will make it right. The lee die & process should not be needed.
Measure your neck diameter of a couple pieces of resized brass. Load bullets into them and then remeasure. What are the measurements? As others have said, you likely have a neck tension issue, but those measurements will tell us more.