the reason this happens is neck tension being to tight
measure your expander button to see how much tension there is against what the projectile size is
in bushing dies it is suggested to used around 2-3 thou, I like under 2 thou but that's me
you may need another expander button
using a vld champfer tool will help guide the flat based projectile in easier
and so will polishing the inside of the neck with a used cleaning brush covered in steel wool
but the case neck being to tight will be the cause
you can try turning the case around after partial seating the projectile, that is a good method for seating projectiles straight
forgot to add do not lock the die down after setting it up, these dies are called wobble dies because they need to wobble to work straight
hope you can sort it out
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